CVE-2026-69664: httpd parks a request worker indefinitely on a malformed chunk size sent after the headers

unknownCVE-2026-69664

CSIRTS triage

vendor: Apache product: httpd Denial of service

What: httpd parks a request worker indefinitely when processing a malformed chunk size sent after headers.
Who is affected: Apache httpd servers configured with chunked transfer encoding support.
Urgency: Moderate; causes denial of service via worker thread exhaustion but requires malformed client input.
Action: Upgrade Apache httpd to a patched version; apply request filtering if available.

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: unknown
Published: 2026-09-02
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69664

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-2026-696640.69% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 50% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-69664	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 httpd parks a

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.

unknownCVE-2026-71380: httpd applies no timeout while receiving a request body, parking a worker on a stalled clientmsrc · 2026-09-02