CVE-2026-80843: Linux

EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux: from 2.6.33, before 5.10.269 (fixed in 5.10.269); from 5.11, before 5.15.220 (fixed in 5.15.220); from 5.16, before 6.1.187 (fixed in 6.1.187); from 6.2, before 6.6.156 (fixed in 6.6.156); from 6.7, before 6.12.108 (fixed in 6.12.108); from 6.13, before 6.18.49 (fixed in 6.18.49); …

Published 2026-09-04. Last modified 2026-09-04.