CVE-2026-2968 MEDIUM

CVE-2026-2968: Cesanta Mongoose Poly1305 Authentication Tag tls_chacha20.c mg_chacha20_poly1305_decrypt signature verification

Vendor Cesanta
Product Mongoose
Weakness CWE-347
Published February 23, 2026
Last update February 23, 2026

CVSS base score

6.3/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

What the vulnerability does

01Description

A vulnerability was detected in Cesanta Mongoose up to 7.20. This impacts the function mg_chacha20_poly1305_decrypt of the file /src/tls_chacha20.c of the component Poly1305 Authentication Tag Handler. The manipulation results in improper verification of cryptographic signature. The attack may be launched remotely. This attack is characterized by high complexity. The exploitability is said to be difficult. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Key dates

02Disclosure timeline

February 23, 2026 CVE published
February 23, 2026 Record updated