Vulnerability 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.
CVSS Score
LOW
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cesanta | Mongoose | >= 7.0, < 7.21 |
Related Weaknesses (CWE)
References
- https://github.com/cesanta/mongoose/releases/tag/7.21Release Notes
- https://github.com/dwBruijn/CVEs/blob/main/Mongoose/AESGCM.mdExploitThird Party Advisory
- https://vuldb.com/submit/796231Third Party AdvisoryVDB Entry
- https://vuldb.com/vuln/359529Third Party AdvisoryVDB Entry
- https://vuldb.com/vuln/359529/ctiPermissions RequiredVDB Entry
FAQ
What is CVE-2026-6986?
CVE-2026-6986 is a vulnerability with a CVSS score of 3.7 (LOW). 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 Hand...
How severe is CVE-2026-6986?
CVE-2026-6986 has been rated LOW with a CVSS base score of 3.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-6986?
Check the references section above for vendor advisories and patch information. Affected products include: Cesanta Mongoose.