CVE-2026-46303: isofs: validate Rock Ridge CE continuation extent against volume size

CSIRTS triage

What

The isofs module fails to validate Rock Ridge CE continuation extent against volume size.

Who is affected

Systems using the isofs module for ISO file systems.

Urgency

Remediation is medium urgency as the severity is moderate and no exploitation has been reported.

Action

Apply the necessary updates to the isofs module.

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

2026-06-09

Exploitation

Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-46303

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-2026-463030.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 20% of all scored CVEs.

Referenced CVEs

Same CVEs, other sources

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

• high[UPDATE] [high] Linux Kernel: Multiple vulnerabilities allow denial of servicecert-bund

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