PT-2026-35156 · Cesanta · Mongoose

Dwbruijn · Published 2026-04-25 · Updated 2026-04-25 · CVE-2026-6985

NVD

CVSS v2.0

5.0

Medium

AV:N/AC:L/Au:N/C:N/I:N/A:P

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.

Exploit

Fix

Infinite Loop

Improper Resource Release

Weakness Enumeration

CWE-835

CWE-404

Related Identifiers

CVE-2026-6985

Affected Products

Mongoose

References · 7

• 🔥 https://github.com/dwBruijn/CVEs/blob/main/Mongoose/TCP_opt_dos.md · Exploit
• https://github.com/cesanta/mongoose/releases/tag/7.21 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-6985 · Security Note
• https://twitter.com/CVEnew/status/2048099261670216188 · Twitter Post
• https://vuldb.com/vuln/359528/cti · Note
• https://vuldb.com/vuln/359528 · Note
• https://vuldb.com/submit/796230 · Note