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.
History

Mon, 27 Apr 2026 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sat, 25 Apr 2026 16:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Cesanta Mongoose GCM Authentication Tag tls_aes128.c mg_aes_gcm_decrypt signature verification
First Time appeared Cesanta
Cesanta mongoose
Weaknesses CWE-345
CWE-347
CPEs cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:*
Vendors & Products Cesanta
Cesanta mongoose
References
Metrics cvssV2_0

{'score': 2.6, 'vector': 'AV:N/AC:H/Au:N/C:N/I:P/A:N/E:POC/RL:OF/RC:C'}

cvssV3_0

{'score': 3.7, 'vector': 'CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C'}

cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C'}

cvssV4_0

{'score': 6.3, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published: 2026-04-25T16:30:13.067Z

Updated: 2026-04-27T13:36:06.578Z

Reserved: 2026-04-24T19:12:51.609Z

Link: CVE-2026-6986

cve-icon Vulnrichment

Updated: 2026-04-27T13:36:01.348Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-25T17:16:33.700

Modified: 2026-04-27T18:57:20.293

Link: CVE-2026-6986

cve-icon Redhat

No data.