CVE-2026-68426: xfrm: fix stale skb->prev after async crypto steals a GSO segment
In the Linux kernel, the following vulnerability has been resolved:
xfrm: fix stale skb->prev after async crypto steals a GSO segment
skbgsosegment() leaves the segment list head with ->prev pointing at the last segment, an invariant validatexmitskblist() relies on when it sets its tail pointer (tail = skb->prev).
When validatexmitxfrm() walks a GSO list and some segments are stolen by async crypto (->xmit() returns -EINPROGRESS), those segments are unlinked from the list but the head ->prev is never updated. If the last segment is the one stolen, the returned head still has ->prev pointing at it, even though it is now owned by the crypto engine and may be freed. validatexmitskblist() later does tail->next = skb, writing through that stale pointer -- a use-after-free.
Repoint skb->prev at the last retained segment before returning.
Other sources
In the Linux kernel, the following vulnerability has been resolved:
xfrm: fix stale skb-prev after async crypto steals a GSO segment
skbgsosegment() leaves the segment list head with -prev pointing at the last segment, an invariant validatexmitskblist() relies on when it sets its tail pointer (tail = skb-prev).
When validatexmitxfrm() walks a GSO list and some segments are stolen by async crypto (-xmit() returns -EINPROGRESS), those segments are unlinked from the list but the head -prev is never updated. If the last segment is the one stolen, the returned head still has -prev pointing at it, even though it is now owned by the crypto engine and may be freed. validatexmitskblist() later does tail-next = skb, writing through that stale pointer -- a use-after-free.
Repoint skb-prev at the last retained segment before returning.
— IBM
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.115-2 - Upgrade
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ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - Upgrade
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ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1024.25~24.04.1 - Upgrade
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ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1035.38 - Upgrade
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ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-38.38 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.1.191 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.6.160 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.114 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.18.42 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 7.1.6 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.116-1Fixed in 7.2.15-1Fixed in 7.3.3-1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-68426?
CVE-2026-68426 has a risk rating of 55, indicating a moderate severity level.
How do I fix CVE-2026-68426?
To fix CVE-2026-68426, update your Linux kernel to the latest version where the vulnerability has been resolved.
What type of vulnerability is CVE-2026-68426?
CVE-2026-68426 is classified as a 'Use After Free' vulnerability.
What components are affected by CVE-2026-68426?
CVE-2026-68426 affects the xfrm subsystem in the Linux kernel.
When was CVE-2026-68426 published?
CVE-2026-68426 was published on August 10, 2026.