CVE-2026-5245

Name	CVE-2026-5245
Description	A vulnerability was found in Cesanta Mongoose up to 7.20. This impacts the function handle_mdns_record of the file mongoose.c of the component mDNS Record Handler. Performing a manipulation of the argument buf results in stack-based buffer overflow. Remote exploitation of the attack is possible. A high degree of complexity is needed for the attack. The exploitability is said to be difficult. The exploit has been made public and could be used. Upgrading to version 7.21 will fix this issue. The patch is named 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. You should upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
mongoose (PTS)	forky, sid	7.21+ds-2	fixed
swupdate (PTS)	bullseye	2020.11-2+deb11u1	vulnerable
	bookworm	2022.12+dfsg-4+deb12u2	vulnerable
	trixie	2024.12.1+dfsg-3+deb13u2	vulnerable
	forky, sid	2025.12+dfsg-10	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
mongoose	source	(unstable)	(not affected)
swupdate	source	(unstable)	2025.12+dfsg-10

Notes

- mongoose <not-affected> (Fixed before or with initial upload)
[trixie] - swupdate <no-dsa> (Minor issue)
[bookworm] - swupdate <no-dsa> (Minor issue)
[bullseye] - swupdate <postponed> (Minor issue)