CVE Catalog

CVE-2026-63919

HighCVSS 8.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.63%

47th percentile - higher than 47% of all known CVEs

Summary

A vulnerability was found in the Linux kernel's xfrm module related to transport-mode packet processing. During deferred transport reinjection, a pointer to the network namespace (netns) stored in skb->cb may become invalid if the namespace is removed before the callback executes.

Risk Assessment

Improper netns reference handling can lead to a use-after-free condition, potentially allowing privilege escalation or denial of service (DoS) on the system.

Recommendation

Immediately update the Linux kernel to a version containing the fix that adds netns reference capture (maybe_get_net) when queuing deferred reinjection and releases it after the callback completes.

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: input: hold netns during deferred transport reinjection Transport-mode reinjection stores a struct net pointer in skb->cb and uses it later from xfrm_trans_reinject(). That pointer must stay valid until the deferred callback runs. Take a netns reference when queueing deferred reinjection work and drop it after the callback completes. Use maybe_get_net() so the queueing path does not revive a namespace that is already being torn down. This keeps the existing workqueue design and fixes the netns lifetime handling in one place for all users of xfrm_trans_queue_net().

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