Vulnerability · CVE-2026-6985
A weakness has been identified in Cesanta Mongoose up to 7.20.
Published Apr 25, 2026 · catalog updated Jun 17, 2026 · A weakness has been
Check if you run it
No confirmed exploitation is on record for CVE-2026-6985. EPSS is 0.92%. Act only if a listed version of A weakness has been is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (A weakness has been).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Medium5.5
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.92%
- Remediation
- Advisory link
- Affected products
- cpe cesanta/mongoose
A weakness has been identified in Cesanta Mongoose up to 7.20. This vulnerability affects the function handle_opt of the file /src/net_builtin.c of the component TCP Option Handler. This manipulation of the argument optlen causes infinite loop. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 7.21 is able to resolve this issue. Upgrading the affected component is advised. VulDB has contacted the vendor early and they confirmed quickly, that this issue got fixed already.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe cesanta/mongooseversion unspecified
How to fix CVE-2026-6985
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-6985. EPSS is 0.92%. Act only if a listed version of A weakness has been is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-404; CWE-835: Infinite Loop. EPSS 0.92%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Apr 25, 2026 · NIST NVD
Detected
A weakness has been identified in Cesanta Mongoose up to 7.20. This vulnerability affects the function handle_opt of the file /src/net_builtin.c of the component TCP Option Handler. This manipulation of the argument optlen causes infinite loop. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 7.
Jun 17, 2026 · NIST NVD
Updated
A weakness has been identified in Cesanta Mongoose up to 7.20. This vulnerability affects the function handle_opt of the file /src/net_builtin.c of the component TCP Option Handler. This manipulation of the argument optlen causes infinite loop. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 7.
Sources
- CVE.orgVulnerability recordCVE-2026-6985
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-6985
30-day exploitation probability 0.9%
first.org - NIST NVDVulnerability recordCVE-2026-6985
A weakness has been identified in Cesanta Mongoose up to 7.20. This vulnerability affects the function handle_opt of the file /src/net_builtin.c of the component TCP Option Handler. This manipulation of the argument optlen causes infinite loop. The attack is possible to be carrie
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.