CVE-2025-21648: netfilter: conntrack: clamp maximum hashtable size to INT_MAX

Q: What is the severity of CVE-2025-21648?

The severity of CVE-2025-21648 is classified as moderate.

Q: How do I fix CVE-2025-21648?

To fix CVE-2025-21648, update your Linux kernel to the latest stable version that contains the patch addressing this vulnerability.

Q: Who is affected by CVE-2025-21648?

CVE-2025-21648 affects users of the Linux kernel who utilize the conntrack module.

Q: What impact does CVE-2025-21648 have on systems?

CVE-2025-21648 can lead to potential memory allocation warnings and degrade system stability during hash table resizing.

Q: Is CVE-2025-21648 exploitable remotely?

CVE-2025-21648 is not directly exploitable remotely but may affect systems processing network traffic that rely on conntrack.

Published Jan 19, 2025

Updated

In the Linux kernel, the following vulnerability has been resolved:

netfilter: conntrack: clamp maximum hashtable size to INTMAX

Use INTMAX as maximum size for the conntrack hashtable. Otherwise, it is possible to hit WARNONONCE in kvmallocnodenoprof() when resizing hashtable because GFPNOWARN is unset. See:

0708a0afe291 ("mm: Consider GFPNOWARN flag for oversized kvmalloc() calls")

Note: hashtable resize is only possible from initnetns.

Other sources

This CVE was automatically created from a reference found in an email or other text. If you are reading this, then this CVE entry is probably erroneous, since this text should be replaced by the official CVE description automatically.

— Launchpad

Affected Software

224 affected componentsFixes available

Linux Linux kernel

IBM Verify Identity Access<=11.0 - 11.0.2

IBM Security Verify Access<=10.0 - 10.0.9.1

IBM Verify Identity Access Container<=11.0 - 11.0.2

IBM Security Verify Access Container<=10.0 - 10.0.9.1

Linux Linux kernel>=4.7.1<5.10.234

Linux Linux kernel>=5.11<5.15.177

Linux Linux kernel>=5.16<6.1.125

Linux Linux kernel>=6.2<6.6.72

Linux Linux kernel>=6.7<6.12.10

Linux Linux kernel=4.7

Linux Linux kernel=6.13-rc1

Linux Linux kernel=6.13-rc2

Linux Linux kernel=6.13-rc3

Linux Linux kernel=6.13-rc4

Linux Linux kernel=6.13-rc5

Linux Linux kernel=6.13-rc6

debian/linux<6.1.128-1

6.1.128-1

debian/linux<6.12.10-1

6.12.10-1

debian/linux<6.12.10-1

6.12.10-1

linux/kernel>=4.7.0<5.10.234

5.10.234

linux/kernel>=5.11.0<5.15.177

5.15.177

linux/kernel>=5.16.0<6.1.125

6.1.125

linux/kernel>=6.2.0<6.6.72

6.6.72

linux/kernel>=6.7.0<6.12.10

6.12.10

ubuntu/linux-azure*

ubuntu/linux-aws-hwe*

ubuntu/linux-azure*

ubuntu/linux-gcp*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-oracle*

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-aws-5.4*

ubuntu/linux-azure*

ubuntu/linux-azure-4.15*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-5.4*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-4.15*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gcp-5.4*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-5.4*

ubuntu/linux-hwe-edge*

ubuntu/linux-ibm-5.4*

ubuntu/linux-kvm*

ubuntu/linux-oem*

ubuntu/linux-oracle*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-oracle-5.4*

ubuntu/linux-raspi-5.4*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-5.15<5.15.0-1080.87~20.04.1

5.15.0-1080.87~20.04.1

ubuntu/linux-azure-5.15<5.15.0-1086.95~20.04.1

5.15.0-1086.95~20.04.1

ubuntu/linux-gcp-5.15<5.15.0-1081.90~20.04.1

5.15.0-1081.90~20.04.1

ubuntu/linux-hwe-5.15<5.15.0-136.147~20.04.1

5.15.0-136.147~20.04.1

ubuntu/linux-ibm-5.15<5.15.0-1074.77~20.04.1

5.15.0-1074.77~20.04.1

ubuntu/linux-intel-iotg-5.15<5.15.0-1077.83~20.04.1

5.15.0-1077.83~20.04.1

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-135.146~20.04.1

5.15.0-135.146~20.04.1

ubuntu/linux-oracle-5.15<5.15.0-1077.83~20.04.1

5.15.0-1077.83~20.04.1

ubuntu/linux-riscv-5.15<5.15.0-1075.79~20.04.1

5.15.0-1075.79~20.04.1

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.8*

ubuntu/linux-azure*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-bluefield*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

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-5.8*

ubuntu/linux-ibm*

ubuntu/linux-intel-5.13*

ubuntu/linux-iot*

ubuntu/linux-kvm*

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1039.39~20.04.1

5.15.0-1039.39~20.04.1

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.8*

ubuntu/linux-xilinx-zynqmp*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux<5.15.0-135.146

5.15.0-135.146

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1080.87

5.15.0-1080.87

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1029.31~22.04.1

6.8.0-1029.31~22.04.1

ubuntu/linux-azure<5.15.0-1084.93

5.15.0-1084.93

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1029.34~22.04.1

6.8.0-1029.34~22.04.1

ubuntu/linux-azure-fde<5.15.0-1084.93.1

5.15.0-1084.93.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp<5.15.0-1079.88

5.15.0-1079.88

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1030.32~22.04.1

6.8.0-1030.32~22.04.1

ubuntu/linux-gke<5.15.0-1077.83

5.15.0-1077.83

ubuntu/linux-gkeop<5.15.0-1062.70

5.15.0-1062.70

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-60.63~22.04.1

6.8.0-60.63~22.04.1

ubuntu/linux-ibm<5.15.0-1072.75

5.15.0-1072.75

ubuntu/linux-ibm-6.8<6.8.0-1026.26~22.04.1

6.8.0-1026.26~22.04.1

ubuntu/linux-intel-iot-realtime<5.15.0-1073.75

5.15.0-1073.75

ubuntu/linux-intel-iotg<5.15.0-1075.81

5.15.0-1075.81

ubuntu/linux-kvm<5.15.0-1076.81

5.15.0-1076.81

ubuntu/linux-lowlatency<5.15.0-135.146

5.15.0-135.146

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-60.63.1~22.04.1

6.8.0-60.63.1~22.04.1

ubuntu/linux-nvidia<5.15.0-1074.75

5.15.0-1074.75

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1028.31~22.04.1

6.8.0-1028.31~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1033.33

5.15.0-1033.33

ubuntu/linux-nvidia-tegra-igx<5.15.0-1021.21

5.15.0-1021.21

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1077.83

5.15.0-1077.83

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1026.27~22.04.1

6.8.0-1026.27~22.04.1

ubuntu/linux-raspi<5.15.0-1074.77

5.15.0-1074.77

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-62.65~22.04.1

6.8.0-62.65~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1044.48

5.15.0-1044.48

ubuntu/linux-bluefield<5.15.0-1062.64

5.15.0-1062.64

ubuntu/linux-realtime<5.15.0-1080.88

5.15.0-1080.88

ubuntu/linux-realtime-6.8<6.8.1-1022.23~22.04.1

6.8.1-1022.23~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1080.87+fips1

5.15.0-1080.87+fips1

ubuntu/linux-azure-fips<5.15.0-1083.92+fips1

5.15.0-1083.92+fips1

ubuntu/linux-fips<5.15.0-135.146+fips1

5.15.0-135.146+fips1

ubuntu/linux-gcp-fips<5.15.0-1079.88+fips1

5.15.0-1079.88+fips1

ubuntu/linux<6.8.0-60.63

6.8.0-60.63

ubuntu/linux-aws<6.8.0-1029.31

6.8.0-1029.31

ubuntu/linux-azure<6.8.0-1029.34

6.8.0-1029.34

ubuntu/linux-azure-6.11<6.11.0-1012.12~24.04.1

6.11.0-1012.12~24.04.1

ubuntu/linux-azure-nvidia<6.8.0-1016.17

6.8.0-1016.17

ubuntu/linux-gcp<6.8.0-1030.32

6.8.0-1030.32

ubuntu/linux-gcp-6.11<6.11.0-1011.11~24.04.1

6.11.0-1011.11~24.04.1

ubuntu/linux-gke<6.8.0-1025.29

6.8.0-1025.29

ubuntu/linux-gkeop<6.8.0-1012.14

6.8.0-1012.14

ubuntu/linux-hwe-6.11<6.11.0-21.21~24.04.1

6.11.0-21.21~24.04.1

ubuntu/linux-ibm<6.8.0-1026.26

6.8.0-1026.26

ubuntu/linux-lowlatency<6.8.0-60.63.1

6.8.0-60.63.1

ubuntu/linux-nvidia<6.8.0-1028.31

6.8.0-1028.31

ubuntu/linux-nvidia-6.11<6.11.0-1007.7

6.11.0-1007.7

ubuntu/linux-nvidia-lowlatency<6.8.0-1028.31.1

6.8.0-1028.31.1

ubuntu/linux-nvidia-tegra<6.8.0-1008.8

6.8.0-1008.8

ubuntu/linux-oem-6.11<6.11.0-1017.17

6.11.0-1017.17

ubuntu/linux-oem-6.8<6.8.0-1028.28

6.8.0-1028.28

ubuntu/linux-oracle<6.8.0-1026.27

6.8.0-1026.27

ubuntu/linux-raspi<6.8.0-1028.32

6.8.0-1028.32

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv<6.8.0-60.63.1

6.8.0-60.63.1

ubuntu/linux-xilinx<6.8.0-1017.18

6.8.0-1017.18

ubuntu/linux-raspi-realtime<6.8.0-2023.24

6.8.0-2023.24

ubuntu/linux-realtime<6.8.1-1022.23

6.8.1-1022.23

ubuntu/linux-fips<6.8.0-78.78+fips1

6.8.0-78.78+fips1

ubuntu/linux-vmware*

debian/linux

6.1.176-16.1.190-16.12.107-16.12.116-17.2.15-17.3.4-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.116-1Fixed in 7.2.15-1Fixed in 7.3.3-1
Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.87~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1086.95~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1081.90~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-136.147~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1074.77~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1075.79~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1039.39~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.87
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1029.31~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1084.93
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1029.34~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1084.93.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1079.88
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1030.32~22.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1062.70
Upgrade
Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-60.63~22.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1072.75
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.26~22.04.1
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1073.75
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1075.81
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1076.81
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-60.63.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1074.75
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.31~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1033.33
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1021.21
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83
Upgrade
Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.27~22.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1074.77
Upgrade
Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-62.65~22.04.1
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1044.48
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1062.64
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.88
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1022.23~22.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.87+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1083.92+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1079.88+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-60.63
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1029.31
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1029.34
Upgrade
Upgrade ubuntu/linux-azure-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1012.12~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1016.17
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1030.32
Upgrade
Upgrade ubuntu/linux-gcp-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1011.11~24.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1025.29
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 6.8.0-1012.14
Upgrade
Upgrade ubuntu/linux-hwe-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-21.21~24.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.26
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-60.63.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.31
Upgrade
Upgrade ubuntu/linux-nvidia-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1007.7
Upgrade
Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.31.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 6.8.0-1008.8
Upgrade
Upgrade ubuntu/linux-oem-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1017.17
Upgrade
Upgrade ubuntu/linux-oem-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.28
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.27
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.32
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 6.8.0-60.63.1
Upgrade
Upgrade ubuntu/linux-xilinx to a version that resolves this vulnerability.
Fixed in 6.8.0-1017.18
Upgrade
Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.
Fixed in 6.8.0-2023.24
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.8.1-1022.23
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78+fips1
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 5.10.234
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 5.15.177
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 6.1.125
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 6.6.72
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 6.12.10
Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.1.128-1
Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.12.10-1
Configuration
Clamp the maximum conntrack hashtable size to INT_MAX.
netfilter conntrack maximum hashtable size = INT_MAX

Event History

Jan 19, 2025

CVE Published

via MITRE·10:18 AM

Data Sourced

via MITRE·10:18 AM

Description

Data Sourced

via OSV·10:18 AM

DescriptionAffected Software

Data Sourced

via Red Hat·11:01 AM

DescriptionSeverityAffected Software

Data Sourced

via NVD·11:15 AM

RemedyDescriptionSeverityAffected Software

Jul 8, 2026

Data Sourced

via IBM·12:00 AM

DescriptionAffected Software

Nov 11, 2026

Data Sourced

via OSV·09:38 AM

Severity

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

What is the severity of CVE-2025-21648?

The severity of CVE-2025-21648 is classified as moderate.

How do I fix CVE-2025-21648?

To fix CVE-2025-21648, update your Linux kernel to the latest stable version that contains the patch addressing this vulnerability.

Who is affected by CVE-2025-21648?

CVE-2025-21648 affects users of the Linux kernel who utilize the conntrack module.

What impact does CVE-2025-21648 have on systems?

CVE-2025-21648 can lead to potential memory allocation warnings and degrade system stability during hash table resizing.

Is CVE-2025-21648 exploitable remotely?

CVE-2025-21648 is not directly exploitable remotely but may affect systems processing network traffic that rely on conntrack.

CVE-2025-21648: netfilter: conntrack: clamp maximum hashtable size to INT_MAX

Other sources

Affected Software

Remediation

Event History

Parent advisories

Peer vulnerabilities

Frequently Asked Questions

What is the severity of CVE-2025-21648?

How do I fix CVE-2025-21648?

Who is affected by CVE-2025-21648?

What impact does CVE-2025-21648 have on systems?

Is CVE-2025-21648 exploitable remotely?

Company

Resources

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