CVE-2026-80843
xfrm: fix xfrm_state_construct() auth-trunc leak
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.
INFO
Published Date :
Sept. 4, 2026, 4:18 p.m.
Last Modified :
Sept. 4, 2026, 4:18 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-80843
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Verify xfrm_state_construct checks if x->aalg is already attached.
- Ensure correct handling of auth algorithms with no sadb_alg_id.
- Update the Linux kernel to the latest patched version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-80843.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-80843 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-80843
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-80843 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-80843 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 04, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80843.json">CVE-2026-80843</a> Added Reference https://git.kernel.org/stable/c/37426395cb90ef217beec8407a14bd82153793d3 Added Reference https://git.kernel.org/stable/c/71d42da01740ec6557837bebec0bc48cfc3b4c39 Added Reference https://git.kernel.org/stable/c/958ae9f261319e1cdc44879886bcda2263258cca Added Reference https://git.kernel.org/stable/c/ba0c110c205855b3f1e3130d8c0fdb484d704c8c Added Reference https://git.kernel.org/stable/c/be19d20e53a239572bb2a28efcc1cd2b069b1ef9 Added Reference https://git.kernel.org/stable/c/c12cbf56320fb633484ee0ca1fb7d68d6b64b213 Added Reference https://git.kernel.org/stable/c/c8837bbe792257af547fd1c0252553ce13148795 Added Reference https://git.kernel.org/stable/c/cf67361e78dca488d6e4df8396a53e6745a3a80e Added Reference https://git.kernel.org/stable/c/fb7f3e74789a3c89647f4eb768f6dfaf4a751e72