CVE-2026-64581: xfrm: fix sk_dst_cache double-free in xfrm_user_policy()

mediumCVSS 5.1CVE-2026-64581

CSIRTS triage

vendor: Linux product: Linux Kernel Memory corruption

What: A double-free vulnerability exists in xfrm_user_policy() when sk_dst_cache is improperly released.
Who is affected: Systems running Linux kernel with xfrm/IPsec subsystem enabled.
Urgency: Medium priority; CVSS 5.1, double-free can cause crash or memory corruption.
Action: Apply kernel patch fixing sk_dst_cache release logic in xfrm_user_policy.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 5.1
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64581

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-2026-645810.11% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-64581	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

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.

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criticalCVE-2026-72451: In the Linux kernel, the following vulnerability has been resolved: xfrm: Fix xfrm state cache…nvd · 2026-08-15
highCVE-2026-72450: In the Linux kernel, the following vulnerability has been resolved: xfrm: validate selector fa…nvd · 2026-08-15
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highCVE-2026-72136: In the Linux kernel, the following vulnerability has been resolved: xfrm: xfrm_interface: requ…nvd · 2026-08-15
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