CVE-2026-73257
critical · 9.1Mongoose 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.
9.1
CVSS
0.7%
EPSS (exploit prob.)
52nd
EPSS percentile
2026-08-20
Published
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weaknesses
CWE-444
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| cesanta | mongoose | < 7.22 |
Check a specific version with /api/v1/cve/match.
References
- 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
- https://github.com/cesanta/mongoose/security/advisories/GHSA-5wfq-r6mr-wqp6
Query this programmatically:
curl https://evil-db.io/api/v1/cve/CVE-2026-73257