CVE Catalog

CVE-2026-31663

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.22%

13th percentile - higher than 13% of all known CVEs

Summary

In the Linux kernel, a vulnerability was found in the xfrm subsystem where, after async crypto completion, xfrm_input_resume() immediately released the device reference (dev_put()) before the skb reached transport_finish and NF_HOOK. This caused a race condition with device teardown, as skb->dev was used after the reference was dropped.

Risk Assessment

An attacker could exploit this race condition to access freed device memory, potentially leading to a kernel panic or use-after-free that may allow privilege escalation.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit that removes the premature dev_put() and defers the reference release after NF_HOOK). Check your distribution for the patch and apply it urgently.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: xfrm: hold dev ref until after transport_finish NF_HOOK After async crypto completes, xfrm_input_resume() calls dev_put() immediately on re-entry before the skb reaches transport_finish. The skb->dev pointer is then used inside NF_HOOK and its okfn, which can race with device teardown. Remove the dev_put from the async resumption entry and instead drop the reference after the NF_HOOK call in transport_finish, using a saved device pointer since NF_HOOK may consume the skb. This covers NF_DROP, NF_QUEUE and NF_STOLEN paths that skip the okfn. For non-transport exits (decaps, gro, drop) and secondary async return points, release the reference inline when async is set.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS