# CVE-2026-73258

## Summary

- **CVE ID:** CVE-2026-73258
- **Severity:** MEDIUM
- **CVSS Score:** 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N)
- **CWE:** CWE-697
- **Published:** Aug 20, 2026
- **Last Modified:** Aug 20, 2026

## Description

Mongoose is an embedded web server and network library. Prior to 7.22, a remote attacker can place a lone carriage return or line feed in multipart input processed by mg_http_next_multipart() in src/http.c. The loops comparing s[b] and s[b + 1], and s[h2] and s[h2 + 1], use an incorrect AND condition and stop when either character resembles part of a CRLF terminator. This truncates headers, filenames, or boundaries and can cause an application to accept dangerous content after seeing a misleading Content-Type value. This issue is fixed in version 7.22.

## Affected Products

- cesanta — mongoose (< 7.22)

## References

- [CNA](https://github.com/cesanta/mongoose/security/advisories/GHSA-cc55-8v3r-59p8)
- [CNA](https://github.com/cesanta/mongoose/pull/3611)
- [CNA](https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71)
- [CNA](https://github.com/cesanta/mongoose/releases/tag/7.22)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.27%
- **EPSS Percentile:** 18.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._