Home/CVE/A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This issue affects the function mg_aes_gcm_de
CVE

CVE-2026-6986

A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This issue affects the function mg_aes_gcm_de

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.

LOW · CVSS 3.7 EPSS 7e-05
Schedule remediation
  • Public exploit or PoC is available
Sigma rules0 YARA rules0

Affected Products & Versions

1
cesanta mongoose>= 7.0 and < 7.21

Public Exploits & PoCs

1

Scoring & Timeline

3.7
LOW · CVSS v3.1 · cna@vuldb.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD25 Apr 2026 · 05:16 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
SSVC triage · cisa-vulnrichment
Exploitation
poc
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
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References & Sources

4
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://vuldb.com/submit/796231Third Party AdvisoryVDB Entry
https://vuldb.com/vuln/359529Third Party AdvisoryVDB Entry
https://vuldb.com/vuln/359529/ctiPermissions RequiredVDB Entry
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