CVE-2026-6985
highpriority · track · 30EPSS 0.006 · 47 %ileEUUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–high · 2.7–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (22)
Products and version ranges known to be affected.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (13)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2026-6985cnnvd
- https://github.com/cesanta/mongoose/releases/Patchcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2026-6985cnnvd
- https://github.com/cesanta/mongoose/releases/tag/7.21enisa_euvd
- https://github.com/dwBruijn/CVEs/blob/main/Mongoose/TCP_opt_dos.mdenisa_euvd
- https://vuldb.com/submit/796230enisa_euvd
- https://vuldb.com/vuln/359528enisa_euvd
- https://vuldb.com/vuln/359528/ctienisa_euvd
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