HTTP Request Smuggling Affecting mongoose package, versions <7.22+ds-1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published22 Aug 2026
- disclosed20 Aug 2026
Introduced: 20 Aug 2026
NewCVE-2026-73257 (opens in a new tab)How to fix?
Upgrade Debian:unstable mongoose to version 7.22+ds-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream mongoose package and not the mongoose package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
Mongoose is an embedded web server and network library. Priro to version 7.22, a remote unauthenticated attacker can send an HTTP request containing both Content-Length and Transfer-Encoding: chunked. The cl_count and te_count checks in the mg_http_parse() and http_cb() paths in src/http.c accept both headers and prioritize chunked encoding, while a Content-Length-preferring reverse proxy can use a different request boundary. This CL.TE desynchronization can inject requests that access or modify resources in another user context. This issue is fixed in version 7.22.
References
- https://security-tracker.debian.org/tracker/CVE-2026-73257
- https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71
- https://github.com/cesanta/mongoose/pull/3611
- https://github.com/cesanta/mongoose/releases/tag/7.22
- https://github.com/cesanta/mongoose/security/advisories/GHSA-5wfq-r6mr-wqp6