CVE-2026-6985

MEDIUM

Cesanta Mongoose TCP Option net_builtin.c handle_opt infinite loop

Title source: cna
STIX 2.1

Description

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.

Scores

CVSS v3 5.3
EPSS 0.0015
EPSS Percentile 34.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-404 CWE-835
Status published
Products (23)
Cesanta/Mongoose 7.0
cesanta/mongoose 7.0 - 7.21
Cesanta/Mongoose 7.1
Cesanta/Mongoose 7.10
Cesanta/Mongoose 7.11
Cesanta/Mongoose 7.12
Cesanta/Mongoose 7.13
Cesanta/Mongoose 7.14
Cesanta/Mongoose 7.15
Cesanta/Mongoose 7.16
... and 13 more
Published Apr 25, 2026
Tracked Since Apr 25, 2026