CVE-2026-74598: ipv6: fix Route Information option length validation

mediumCVSS 5.4CVE-2026-74598

CSIRTS triage

Denial of service

What: Route Information option length validation is missing or insufficient, allowing malformed ICMPv6 packets.
Who is affected: IPv6-enabled systems receiving untrusted IPv6 packets with malformed Route Information options.
Urgency: Medium severity DoS potential; patch to prevent kernel handling of invalid RA options.
Action: Apply the kernel patch that validates Route Information option lengths in ICMPv6 processing.

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 5.4
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-74598

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-2026-745980.43% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 35% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-74598	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 ipv6

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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