CVE-2026-6985A weakness has been identified in Cesanta Mongoose up to 7.20.
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-404, CWE-835
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jun 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
cesanta mongoose cesanta:mongoose | from 7.0 before 7.21 | NVD |
References
- https://github.com/cesanta/mongoose/releases/tag/7.21product, release-notes
- https://github.com/dwBruijn/CVEs/blob/main/Mongoose/TCP_opt_dos.mdexploit, third-party-advisory
- https://vuldb.com/submit/796230third-party-advisory, vdb-entry
- https://vuldb.com/vuln/359528third-party-advisory, vdb-entry
- https://vuldb.com/vuln/359528/ctipermissions-required, vdb-entry
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.