PT-2026-35157 · Cesanta · Mongoose

Dwbruijn · Published 2026-04-25 · Updated 2026-04-25 · CVE-2026-6986

Mitre

CVSS v3.1

3.7

Low

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

A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This issue affects the function mg aes gcm decrypt of the file /src/tls aes128.c of the component GCM Authentication Tag Handler. Such manipulation leads to improper verification of cryptographic signature. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is assessed as difficult. The exploit has been disclosed publicly and may be used. Upgrading to version 7.21 is capable of addressing this issue. It is advisable to upgrade the affected component. VulDB has contacted the vendor early and they confirmed quickly, that this issue got fixed already.

Exploit

Fix

Improper Verification of Cryptographic Signature

Insufficient Verification of Data Authenticity

Weakness Enumeration

CWE-347

CWE-345

Related Identifiers

CVE-2026-6986

Affected Products

Mongoose

References · 8

• 🔥 https://github.com/dwBruijn/CVEs/blob/main/Mongoose/AESGCM.md · Exploit
• https://github.com/cesanta/mongoose/releases/tag/7.21 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-6986 · Security Note
• https://twitter.com/VulmonFeeds/status/2048097514717323311 · Twitter Post
• https://vuldb.com/submit/796231 · Note
• https://vuldb.com/vuln/359529 · Note
• https://vuldb.com/vuln/359529/cti · Note
• https://twitter.com/CVEnew/status/2048099260663574871 · Twitter Post