PT-2026-35156 · Cesanta · Mongoose

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

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Cesanta Mongoose versions prior to 7.21

Description A weakness in the TCP Option Handler component allows a remote attacker to cause an infinite loop. This occurs through the manipulation of the optlen argument within the handle opt() function located in the /src/net builtin.c file.

Recommendations Update to version 7.21.

Exploit

Fix

Improper Resource Release

Infinite Loop

Weakness Enumeration

CWE-404

CWE-835

Related Identifiers

CVE-2026-6985

Affected Products

Mongoose

References · 9

• 🔥 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://osv.dev/vulnerability/DEBIAN-CVE-2026-6985 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-6985 · Vendor Advisory
• https://vuldb.com/vuln/359528 · Note
• https://twitter.com/CVEnew/status/2048099261670216188 · Twitter Post
• https://vuldb.com/vuln/359528/cti · Note
• https://vuldb.com/submit/796230 · Note