Cross-site Scripting (XSS) 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-2026-73259 (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. Prior to 7.22, a remote attacker can send a crafted percent-encoded request path to a deployment using MG_ENABLE_DIRLIST and persuade a user to visit it. The mg_http_serve_dir() and listdir() path in src/http.c places the decoded request URI into the title and h1 elements without HTML entity encoding. The resulting reflected cross-site scripting executes in the Mongoose origin and can expose session data or perform actions as the victim. This issue is fixed in version 7.22.
References
- https://security-tracker.debian.org/tracker/CVE-2026-73259
- 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-9cwm-487w-h25w