CVE-2026-80843

xfrm: fix xfrm_state_construct() auth-trunc leak

State: Published
Severity: Not scored
Published: Sep 4, 2026
Updated: Oct 19, 2026
Reserved: Aug 26, 2026

Description

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	4447bb33f09444920a8f1d89e1540137429351b6 to before 958ae9f261319e1cdc44879886bcda2263258ccaAffected 4447bb33f09444920a8f1d89e1540137429351b6 to before fb7f3e74789a3c89647f4eb768f6dfaf4a751e72Affected 4447bb33f09444920a8f1d89e1540137429351b6 to before ba0c110c205855b3f1e3130d8c0fdb484d704c8cAffected 4447bb33f09444920a8f1d89e1540137429351b6 to before c8837bbe792257af547fd1c0252553ce13148795Affected 4447bb33f09444920a8f1d89e1540137429351b6 to before 71d42da01740ec6557837bebec0bc48cfc3b4c39Affected 4447bb33f09444920a8f1d89e1540137429351b6 to before cf67361e78dca488d6e4df8396a53e6745a3a80eAffected 4447bb33f09444920a8f1d89e1540137429351b6 to before 37426395cb90ef217beec8407a14bd82153793d3Affected 4447bb33f09444920a8f1d89e1540137429351b6 to before be19d20e53a239572bb2a28efcc1cd2b069b1ef9Affected 4447bb33f09444920a8f1d89e1540137429351b6 to before c12cbf56320fb633484ee0ca1fb7d68d6b64b213Affected
LinuxLinux	2.6.33Affected before 2.6.33Not affected 5.10.269 through 5.10.Not affected 5.15.220 through 5.15.Not affected 6.1.187 through 6.1.Not affected 6.6.156 through 6.6.Not affected 6.12.108 through 6.12.Not affected 6.18.49 through 6.18.Not affected 7.1.13 through 7.1.Not affected 7.2.3 through 7.2.Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

4447bb33f09444920a8f1d89e1540137429351b6 to before 958ae9f261319e1cdc44879886bcda2263258ccaAffected
4447bb33f09444920a8f1d89e1540137429351b6 to before fb7f3e74789a3c89647f4eb768f6dfaf4a751e72Affected
4447bb33f09444920a8f1d89e1540137429351b6 to before ba0c110c205855b3f1e3130d8c0fdb484d704c8cAffected
4447bb33f09444920a8f1d89e1540137429351b6 to before c8837bbe792257af547fd1c0252553ce13148795Affected
4447bb33f09444920a8f1d89e1540137429351b6 to before 71d42da01740ec6557837bebec0bc48cfc3b4c39Affected
4447bb33f09444920a8f1d89e1540137429351b6 to before cf67361e78dca488d6e4df8396a53e6745a3a80eAffected
4447bb33f09444920a8f1d89e1540137429351b6 to before 37426395cb90ef217beec8407a14bd82153793d3Affected
4447bb33f09444920a8f1d89e1540137429351b6 to before be19d20e53a239572bb2a28efcc1cd2b069b1ef9Affected
4447bb33f09444920a8f1d89e1540137429351b6 to before c12cbf56320fb633484ee0ca1fb7d68d6b64b213Affected

LinuxLinux

2.6.33Affected
before 2.6.33Not affected
5.10.269 through 5.10.*Not affected
5.15.220 through 5.15.*Not affected
6.1.187 through 6.1.*Not affected
6.6.156 through 6.6.*Not affected
6.12.108 through 6.12.*Not affected
6.18.49 through 6.18.*Not affected
7.1.13 through 7.1.*Not affected
7.2.3 through 7.2.*Not affected
7.3 and laterNot affected

References

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