CVE-2026-80843: xfrm: fix xfrm_state_construct() auth-trunc leak

lowCVSS 2.3CVE-2026-80843

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: low — CVSS 2.3
Published: 2026-09-08
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80843

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-808430.19% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 9% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-80843	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

unknownCVE-2026-80843: In the Linux kernel, the following vulnerability has been resolved: xfrm: fix xfrm_state_const…nvd

Recent advisories for xfrm

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

mediumCVE-2026-80848: xfrm: espintcp: fix UAF during closemsrc · 2026-09-08
mediumCVE-2026-80844: xfrm: ah6: validate routing header segments_leftmsrc · 2026-09-08
mediumCVE-2026-80846: xfrm: drop ESP-in-TCP packets with no ingress devicemsrc · 2026-09-08
medium[UPDATE] [mittel] Linux Kernel (xfrm: iptfs): Schwachstelle ermöglicht DoS und Manipulation von Datencert-bund · 2026-09-07
unknownCVE-2026-80848: In the Linux kernel, the following vulnerability has been resolved: xfrm: espintcp: fix UAF du…nvd · 2026-09-04
unknownCVE-2026-80846: In the Linux kernel, the following vulnerability has been resolved: xfrm: drop ESP-in-TCP pack…nvd · 2026-09-04