CVE-2026-80843

In the Linux kernel, the following vulnerability has been resolved: xfrm: fix xfrm_state_construct() auth-trunc leak attach_auth_trunc() can allocate x->aalg while leaving x->props.aalgo at zero when the selected auth algorithm has no sadb_alg_id. One real case is cmac(aes). xfrm_state_construct() then treats !x->props.aalgo as "no auth algorithm attached yet" and calls attach_auth(). That overwrites x->aalg and loses the first allocation. Any later failure or teardown only frees the replacement pointer. Check whether x->aalg is already attached instead of inferring that state from x->props.aalgo.

EPSS

0.2% chance of exploitation in the next 30 days; higher than 9% of CVEs (scores of 2026-10-25)

Published

2026-09-04

Modified

2026-10-19

Record from

the NVD, synced 2026-10-19

References

• https://git.kernel.org/stable/c/37426395cb90ef217beec8407a14bd82153793d3
• https://git.kernel.org/stable/c/71d42da01740ec6557837bebec0bc48cfc3b4c39
• https://git.kernel.org/stable/c/958ae9f261319e1cdc44879886bcda2263258cca
• https://git.kernel.org/stable/c/ba0c110c205855b3f1e3130d8c0fdb484d704c8c
• https://git.kernel.org/stable/c/be19d20e53a239572bb2a28efcc1cd2b069b1ef9

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