CVE-2026-64317: isofs: bound Rock Ridge symlink components to the SL record

mediumCVSS 5.5CVE-2026-64317

CSIRTS triage

What: Rock Ridge symlink components are not bounded to the SL record.
Who is affected: Deployments using isofs may be affected.
Urgency: Remediation urgency is unclear due to unknown severity and exploitation status.
Action: Monitor for updates regarding this issue.

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

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 5.5
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64317

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-2026-643170.16% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 6% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-64317	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

highCVE-2026-64317: In the Linux kernel, the following vulnerability has been resolved: isofs: bound Rock Ridge sy…nvd

Recent advisories for isofs

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.

highCVE-2026-64317: In the Linux kernel, the following vulnerability has been resolved: isofs: bound Rock Ridge sy…nvd · 2026-07-25
mediumCVE-2026-46303: isofs: validate Rock Ridge CE continuation extent against volume sizemsrc · 2026-06-09