Bug 2558505 (CVE-2026-111817)

Summary:	CVE-2026-111817 trafficserver: trafficserver: Denial of Service via dropped chunked trailers
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Security
Target Milestone:	---
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in Apache Traffic Server. When configured to drop HTTP chunked trailers, the proxy incorrectly waits for data bytes that it has already discarded, stalling the transfer until the connection times out. A remote attacker can exploit this condition by sending chunked transfers, resulting in a Denial of Service (DoS) for affected connections.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2562344, 2562346
Bug Blocks:

Description OSIDB Bzimport 2026-10-21 19:32:21 UTC

Apache Traffic Server can stall a chunked transfer that it passes through with its trailers removed (proxy.config.http.drop_chunked_trailers) until the connection times out, because it waits for the trailer bytes it has already dropped. Trailer dropping is on by default in 10.x. In 8.1.11 and 9.2.x it is off by default, and those versions are affected only if it is enabled.



This issue affects Apache Traffic Server: 8.1.11, from 9.2.5 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.



Users are recommended to upgrade to version 10.1.5 or 10.2.1, which fix the issue.