Bug 2528802 (CVE-2026-18149) - CVE-2026-18149 undici: undici: Denial of Service due to orphaned response body in retry handler
Summary: CVE-2026-18149 undici: undici: Denial of Service due to orphaned response bod...
Keywords:
Status: MODIFIED
Alias: CVE-2026-18149
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2529454
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-04 17:35 UTC by OSIDB Bzimport
Modified: 2026-09-08 14:42 UTC (History)
54 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-09-04 17:35:56 UTC
undici's retry handler can leave an already-exposed response body pending forever. When a server returns a successful response that declares a Content-Length, sends only part of the body, and closes the connection, the retry handler retries the request. If the retry returns a non-retryable status such as 400, the handler forwards that new response downstream and replaces its internal response stream, but the original response body that the application still holds is never ended or destroyed. As a result calls that read that body never settle, and the configured body timeout does not fire because its timer is tied to the connection parser rather than the orphaned body. An attacker-controlled server can trigger this with two short responses without keeping a connection open, and repeated requests accumulate pending promises and streams that can exhaust application concurrency or memory. This affects undici versions from 7.11.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.

Comment 1 Jan Staněk 2026-09-08 14:42:20 UTC
Update has been submitted to rawhide: https://bodhi.fedoraproject.org/updates/FEDORA-2026-c6c3d48699


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