UBUNTU-CVE-2026-64560: High severity ubuntu/linux-hwe-edge vulnerability

Published Jul 29, 2026
·
Updated

In the Linux kernel, the following vulnerability has been resolved: posix-cpu-timers: Prevent UAF caused by non-leader exec() race Wongi and Jungwoo decoded and reported a non-leader exec() related race which can result in an UAF: systimerdelete() exec() posixcputimerdel() // Observes old leader p = pidtask(pid, pidtype); dethread() switchleader(); releasetask(oldleader) exitsignal(oldleader) sighand = lock(oldleader, sighand); posixcputimersexit(); sighand = locktasksighand(p) unhashtask(oldleader); sh = lock(p, sighand) oldleader->sighand = NULL; unlock(sighand); (p->sighand == NULL) unlock(sh) return NULL; // Returns without action if(!sighand) return 0; freeposixtimer(); This is "harmless" unless the deleted timer was armed and enqueued in p->signal because on exec() a TGID targeted timer is inherited. As systimerdelete() freed the underlying posix timer object runposixcputimers() or any timerqueue related add/delete operations on other timers will access the freed object's timerqueue node, which results in an UAF. There is a similar problem vs. posixcputimerset(). For regular posix timers it just transiently returns -ESRCH to user space, but for the use case in docpunanosleep() it's the same UAF just that the kitimer is allocated on the stack. Also posixcputimerrearm() fails to rearm the timer, which means it stops to expire. While debating solutions Frederic pointed out another problem: posixcputimerdel(tmr) exitsignal(p) posixcputimersexit(p); unhashtask(p); p->sighand = NULL; sh = locktasksighand(p) sighand = p->sighand; if (!sighand) return NULL; lock(sighand); if (!sh) WARNONONCE(timerqueued(tmr)); On weakly ordered architectures it is not guaranteed that posixcputimerdel() will observe the stores in posixcputimersexit() when p->sighand is observed as NULL, which means the WARN() can be a false positive. Solve these issues by: 1) Changing the store in exitsignal() to smpstorerelease(). 2) Adding a smpacquireafterctrldep() into the !sighand path of locktasksighand(). 3) Creating a helper function for looking up the task and locking sighand which does not return when sighand == NULL. Instead it retries the task lookup and only if that fails it gives up. 4) Using that helper in the three affected functions. #1/#2 ensures that the reader side which observes sighand == NULL also observes all preceeding stores, i.e. the stores in posixcputimersexit() and the ones in unhashtask(). #3 ensures that the above described non-leader exec() situation is handled gracefully. When the task lookup returns the old leader, but sighand == NULL then it retries. In the non-leader exec() case the subsequent task lookup will observe the new leader due to #1/#2. In normal exit() scenarios the subsequent lookup fails. When the task lookup fails, the function also checks whether the timer is still enqueued and issues a warning if that's the case. Unfortunately there is nothing which can be done about it, but as the task is already not longer visible the timer should not be accessed anymore. This check also requires memory ordering, which is not provided when the first lookup fails. To achieve that the check is preceeded by a smprmb() which pairs with the smpwmb() in writeseqlock() in exitsignal(). That ensures that the stores in posixcputimersexit() are visible. The history of the non-leader exec() issue goes back to the early days of posix CPU timers, which stored a pointer to the group leader task in the timer. That obviously fails when a non-leader exec() switches the leader. commit e0a70217107e ("posix-cpu-timers: workaround to suppress the problems with mt exec") added a temporary workaround for that in 2010 which surv ---truncated---

Affected Software

200 affected componentsFixes available
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.15<5.15.0-1117.124~20.04.1
5.15.0-1117.124~20.04.1
ubuntu/linux-aws-5.8*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.15<5.15.0-1123.132~20.04.1
5.15.0-1123.132~20.04.1
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15<5.15.0-1122.131~20.04.1
5.15.0-1122.131~20.04.1
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.15<5.15.0-1118.128~20.04.1
5.15.0-1118.128~20.04.1
ubuntu/linux-gcp-5.8*
ubuntu/linux-gke*
ubuntu/linux-gke-5.15*
ubuntu/linux-gkeop*
ubuntu/linux-gkeop-5.15*
ubuntu/linux-hwe-5.11*
ubuntu/linux-hwe-5.13*
ubuntu/linux-hwe-5.15<5.15.0-198.208~20.04.1
5.15.0-198.208~20.04.1
ubuntu/linux-hwe-5.8*
ubuntu/linux-ibm-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-intel-5.13*
ubuntu/linux-intel-iotg-5.15<5.15.0-1112.118~20.04.1
5.15.0-1112.118~20.04.1
ubuntu/linux-lowlatency-hwe-5.15<5.15.0-195.205~20.04.1
5.15.0-195.205~20.04.1
ubuntu/linux-nvidia-tegra-5.15*
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.15<5.15.0-1114.120~20.04.1
5.15.0-1114.120~20.04.1
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-riscv-5.8*
ubuntu/linux<5.15.0-198.208
5.15.0-198.208
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws<5.15.0-1117.124
5.15.0-1117.124
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8*
ubuntu/linux-azure<5.15.0-1123.132
5.15.0-1123.132
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8*
ubuntu/linux-azure-fde<5.15.0-1122.131
5.15.0-1122.131
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8*
ubuntu/linux-gcp<5.15.0-1118.128
5.15.0-1118.128
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8*
ubuntu/linux-gke<5.15.0-1113.119
5.15.0-1113.119
ubuntu/linux-gkeop<5.15.0-1100.108
5.15.0-1100.108
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-ibm<5.15.0-1111.115
5.15.0-1111.115
ubuntu/linux-ibm-6.8*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-intel-iotg<5.15.0-1112.118
5.15.0-1112.118
ubuntu/linux-kvm<5.15.0-1109.114
5.15.0-1109.114
ubuntu/linux-lowlatency<5.15.0-195.205
5.15.0-195.205
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8*
ubuntu/linux-nvidia<5.15.0-1112.113
5.15.0-1112.113
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8*
ubuntu/linux-nvidia-tegra*
ubuntu/linux-nvidia-tegra-igx*
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle<5.15.0-1114.120
5.15.0-1114.120
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8*
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8*
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-xilinx-zynqmp<5.15.0-1080.84
5.15.0-1080.84
ubuntu/linux-bluefield<5.15.0-1101.103
5.15.0-1101.103
ubuntu/linux-intel-iot-realtime<5.15.0-1109.111
5.15.0-1109.111
ubuntu/linux-realtime<5.15.0-1116.125
5.15.0-1116.125
ubuntu/linux-realtime-6.8*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips<5.15.0-1117.124+fips1
5.15.0-1117.124+fips1
ubuntu/linux-azure-fips<5.15.0-1123.132+fips1
5.15.0-1123.132+fips1
ubuntu/linux-fips<5.15.0-198.208+fips1
5.15.0-198.208+fips1
ubuntu/linux-gcp-fips<5.15.0-1118.128+fips1
5.15.0-1118.128+fips1
ubuntu/linux<6.8.0-147.147
6.8.0-147.147
ubuntu/linux-aws<6.8.0-1067.70
6.8.0-1067.70
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17*
ubuntu/linux-aws-7.0<7.0.0-1014.14~24.04.1
7.0.0-1014.14~24.04.1
ubuntu/linux-azure<6.8.0-1071.79
6.8.0-1071.79
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17*
ubuntu/linux-azure-7.0<7.0.0-1017.17~24.04.1
7.0.0-1017.17~24.04.1
ubuntu/linux-azure-fde<6.8.0-1069.76
6.8.0-1069.76
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-fde-6.17*
ubuntu/linux-azure-fde-7.0<7.0.0-1016.16~24.04.1
7.0.0-1016.16~24.04.1
ubuntu/linux-azure-nvidia*
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp<6.8.0-1071.79
6.8.0-1071.79
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-7.0<7.0.0-1014.14~24.04.1
7.0.0-1014.14~24.04.1
ubuntu/linux-gke<6.8.0-1066.74
6.8.0-1066.74
ubuntu/linux-gkeop<6.8.0-1052.56
6.8.0-1052.56
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17*
ubuntu/linux-hwe-7.0<7.0.0-38.38~24.04.4
7.0.0-38.38~24.04.4
ubuntu/linux-ibm<6.8.0-1067.68
6.8.0-1067.68
ubuntu/linux-lowlatency<6.8.0-147.147.1
6.8.0-147.147.1
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17*
ubuntu/linux-nvidia-7.0*
ubuntu/linux-nvidia-lowlatency*
ubuntu/linux-nvidia-tegra<6.8.0-1036.39
6.8.0-1036.39
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17*
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle<6.8.0-1064.67
6.8.0-1064.67
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17*
ubuntu/linux-oracle-7.0<7.0.0-1013.13~24.04.1
7.0.0-1013.13~24.04.1
ubuntu/linux-raspi*
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17*
ubuntu/linux-riscv-7.0<7.0.0-38.38.1~24.04.1
7.0.0-38.38.1~24.04.1
ubuntu/linux-xilinx*
ubuntu/linux-bluefield<6.8.0-1033.38
6.8.0-1033.38
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime<6.8.1-1062.63
6.8.1-1062.63
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17*
ubuntu/linux-aws-fips<6.8.0-1067.70+fips1
6.8.0-1067.70+fips1
ubuntu/linux-azure-fips<6.8.0-1071.79+fips1
6.8.0-1071.79+fips1
ubuntu/linux-fips<6.8.0-147.147+fips1
6.8.0-147.147+fips1
ubuntu/linux-gcp-fips<6.8.0-1071.79+fips1
6.8.0-1071.79+fips1
ubuntu/linux<7.0.0-38.38
7.0.0-38.38
ubuntu/linux-aws<7.0.0-1014.14
7.0.0-1014.14
ubuntu/linux-azure<7.0.0-1017.17
7.0.0-1017.17
ubuntu/linux-azure-fde<7.0.0-1016.16
7.0.0-1016.16
ubuntu/linux-gcp<7.0.0-1014.14
7.0.0-1014.14
ubuntu/linux-gke<7.0.0-1008.9
7.0.0-1008.9
ubuntu/linux-ibm<7.0.0-1015.15
7.0.0-1015.15
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-bos*
ubuntu/linux-oem-7.0<7.0.0-1015.15
7.0.0-1015.15
ubuntu/linux-oracle<7.0.0-1013.13
7.0.0-1013.13
ubuntu/linux-raspi*
ubuntu/linux-realtime<7.0.0-38.38.1
7.0.0-38.38.1
ubuntu/linux-riscv<7.0.0-38.38.1
7.0.0-38.38.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.124~20.04.1
  2. Upgrade

    Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1123.132~20.04.1
  3. Upgrade

    Upgrade ubuntu/linux-azure-fde-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1122.131~20.04.1
  4. Upgrade

    Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1118.128~20.04.1
  5. Upgrade

    Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-198.208~20.04.1
  6. Upgrade

    Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115~20.04.1
  7. Upgrade

    Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.118~20.04.1
  8. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-195.205~20.04.1
  9. Upgrade

    Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1114.120~20.04.1
  10. Upgrade

    Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115~20.04.1
  11. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 5.15.0-198.208
  12. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.124
  13. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 5.15.0-1123.132
  14. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 5.15.0-1122.131
  15. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 5.15.0-1118.128
  16. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 5.15.0-1113.119
  17. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 5.15.0-1100.108
  18. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115
  19. Upgrade

    Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.118
  20. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 5.15.0-1109.114
  21. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 5.15.0-195.205
  22. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.113
  23. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 5.15.0-1114.120
  24. Upgrade

    Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.

    Fixed in 5.15.0-1080.84
  25. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 5.15.0-1101.103
  26. Upgrade

    Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.

    Fixed in 5.15.0-1109.111
  27. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 5.15.0-1116.125
  28. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.124+fips1
  29. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1123.132+fips1
  30. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-198.208+fips1
  31. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1118.128+fips1
  32. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 6.8.0-147.147
  33. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 6.8.0-1067.70
  34. Upgrade

    Upgrade ubuntu/linux-aws-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14~24.04.1
  35. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 6.8.0-1071.79
  36. Upgrade

    Upgrade ubuntu/linux-azure-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1017.17~24.04.1
  37. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 6.8.0-1069.76
  38. Upgrade

    Upgrade ubuntu/linux-azure-fde-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1016.16~24.04.1
  39. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 6.8.0-1071.79
  40. Upgrade

    Upgrade ubuntu/linux-gcp-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14~24.04.1
  41. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 6.8.0-1066.74
  42. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.56
  43. Upgrade

    Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38~24.04.4
  44. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 6.8.0-1067.68
  45. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-147.147.1
  46. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.

    Fixed in 6.8.0-1036.39
  47. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 6.8.0-1064.67
  48. Upgrade

    Upgrade ubuntu/linux-oracle-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13~24.04.1
  49. Upgrade

    Upgrade ubuntu/linux-riscv-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38.1~24.04.1
  50. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 6.8.0-1033.38
  51. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.1-1062.63
  52. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1067.70+fips1
  53. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1071.79+fips1
  54. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-147.147+fips1
  55. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1071.79+fips1
  56. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38
  57. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14
  58. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 7.0.0-1017.17
  59. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 7.0.0-1016.16
  60. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14
  61. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 7.0.0-1008.9
  62. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 7.0.0-1015.15
  63. Upgrade

    Upgrade ubuntu/linux-oem-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1015.15
  64. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13
  65. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38.1
  66. Upgrade

    Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38.1

Event History

Jul 29, 2026
CVE Published
via OSV·05:16 PM
Data Sourced
via OSV·05:16 PM
DescriptionSeverityAffected Software

Frequently Asked Questions

1

Who is realistically exposed to this issue?

Systems running an affected Ubuntu Linux kernel package are exposed where a local user or process can use POSIX CPU timers and trigger the relevant exec race. The provided CVSS vector indicates local access and low privileges are required; no user interaction is required.

2

What does an attacker need to do to exploit it?

An attacker needs to race POSIX CPU timer deletion or setting against a non-leader thread performing exec(). The vulnerable condition involves an armed, enqueued timer inherited during exec, allowing later timer processing or timerqueue operations to access a freed timer object.

3

What is the potential impact?

The race can cause a use-after-free in the kernel. The supplied severity vector rates confidentiality, integrity, and availability impact as high.

4

Are default configurations affected?

The provided data does not state whether affected POSIX CPU timer functionality is enabled or reachable in Ubuntu default configurations.

5

What can be done if patching cannot happen immediately?

The provided data does not include a documented workaround. Reducing untrusted local code execution can reduce exposure because exploitation requires local access.

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