Improper Verification of Source of a Communication Channel Affecting cesanta/mongoose package, versions [,7.21)


Severity

Recommended
0.0
medium
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.49% (39th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-UNMANAGED-CESANTAMONGOOSE-15325856
  • published23 Feb 2026
  • disclosed23 Feb 2026
  • creditdwbruijn

Introduced: 23 Feb 2026

CVE-2026-2967  (opens in a new tab)
CWE-940  (opens in a new tab)

How to fix?

Upgrade cesanta/mongoose to version 7.21 or higher.

Overview

cesanta/mongoose is a networking library for C/C++. It implements event-driven non-blocking APIs for TCP, UDP, HTTP, WebSocket, MQTT.

Affected versions of this package are vulnerable to Improper Verification of Source of a Communication Channel in the getpeer function of the TCP Sequence Number Handler process. An attacker can disrupt established TCP connections by sending specially crafted packets that exploit improper verification of the source of a communication channel.

CVSS Base Scores

version 4.0
version 3.1