Mongoose: Path traversal in SSI #include directives enables arbitrary file read

Description

Mongoose is an embedded web server and network library. Prior to 7.22, an attacker who can control an SSI-enabled file can place directory traversal sequences in an #include file or #include virtual directive. The mg_ssi() function in src/ssi.c concatenates the directive argument into a filesystem path without calling mg_path_is_sane(), allowing an MG_ENABLE_SSI deployment with ssi_pattern configured to disclose files readable by the Mongoose process. This issue is fixed in version 7.22.

Scores

EPSS (exploitation in 30 days)

0.66% · top 48% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: poc · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.

Weakness

• CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (opens in a new tab)All about CWE-22 and its CVEs

Affected products

• cesanta · mongoose

  • affected < 7.22

References (4)

• https://github.com/cesanta/mongoose/security/advisories/GHSA-h7m9-764r-7x4x (opens in a new tab)x_refsource_CONFIRM
• https://github.com/cesanta/mongoose/pull/3611 (opens in a new tab)x_refsource_MISC
• https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71 (opens in a new tab)x_refsource_MISC
• https://github.com/cesanta/mongoose/releases/tag/7.22 (opens in a new tab)x_refsource_MISC

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-73255](https://trackcve.app/badge/CVE-2026-73255.svg)](https://trackcve.app/cve/CVE-2026-73255)

Record last updated 25 Aug 2026, 15:09 UTC.