PT-2026-29692 · Cesanta · Cesanta Mongoose

The_Evilsocket + 1 · Published 2026-04-02 · Updated 2026-04-30 · CVE-2026-5244

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Cesanta Mongoose versions up to 7.20

Description A flaw exists in the TLS 1.3 Handler component of Cesanta Mongoose, specifically within the mg tls recv cert function in the mongoose.c file. Manipulation of the pubkey argument can lead to a heap-based buffer overflow, potentially allowing for remote attacks.

Recommendations Upgrade to version 7.21 or later.

Exploit

Fix

Buffer Overflow

Heap Based Buffer Overflow

Weakness Enumeration

CWE-119

CWE-122

Related Identifiers

CVE-2026-5244

JLSEC-2026-369

Affected Products

Cesanta Mongoose

References · 14

• 🔥 https://vuldb.com/submit/770063 · Exploit
• https://github.com/cesanta/mongoose/commit/0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1 · Patch
• https://github.com/cesanta/mongoose/releases/tag/7.21 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-5244 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-5244 · Vendor Advisory
• https://osv.dev/vulnerability/JLSEC-2026-369 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-5244 · Vendor Advisory
• https://github.com/cesanta/mongoose · Note
• https://evilsocket.net/2026/04/02/Mongoose-Preauth-Remote-Code-Execution-and-mTLS-Bypass · Reddit Post
• https://twitter.com/evilsocket/status/2039656380919886282 · Twitter Post
• https://github.com/advisories/GHSA-7vfw-f3r2-9m2j · Note
• https://twitter.com/CVEnew/status/2039647703282717163 · Twitter Post
• https://vuldb.com/vuln/354825/cti · Note
• https://vuldb.com/vuln/354825 · Note