CVE-2026-73255
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.
INFO
Published Date :
Aug. 20, 2026, 6:16 p.m.
Last Modified :
Sept. 29, 2026, 3:39 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update Mongoose to version 7.22 or later.
- Review and sanitize #include directives in SSI configurations.
- Restrict file access permissions for the Mongoose process.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-73255.
| URL | Resource |
|---|---|
| https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71 | Patch |
| https://github.com/cesanta/mongoose/pull/3611 | Issue Tracking Patch |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | Release Notes |
| https://github.com/cesanta/mongoose/security/advisories/GHSA-h7m9-764r-7x4x | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-73255 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-73255
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-73255 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-73255 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Sep. 29, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:* versions up to (excluding) 7.22 Added Reference Type GitHub, Inc.: https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/cesanta/mongoose/pull/3611 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/cesanta/mongoose/releases/tag/7.22 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/cesanta/mongoose/security/advisories/GHSA-h7m9-764r-7x4x Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 25, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-73255', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-25T15:09:21.374366Z'} -
New CVE Received by [email protected]
Aug. 20, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'cesanta', 'product': 'mongoose', 'versions': [{'status': 'affected', 'version': '< 7.22'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-22 Added Reference https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71 Added Reference https://github.com/cesanta/mongoose/pull/3611 Added Reference https://github.com/cesanta/mongoose/releases/tag/7.22 Added Reference https://github.com/cesanta/mongoose/security/advisories/GHSA-h7m9-764r-7x4x