CVE-2026-93563

NameCVE-2026-93563
DescriptionA flaw was found in Netty's `SmtpResponseDecoder` component. A remote attacker, acting as a malicious or man-in-the-middle (MITM) SMTP server, could exploit this by sending a specially crafted, unbounded multi-line SMTP response without a terminator. This vulnerability leads to unbounded memory accumulation within the client's Java Virtual Machine (JVM) heap, causing an `OutOfMemoryError` and a denial of service (DoS) due to a process crash.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1148396

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
netty (PTS)bookworm, bookworm (security)1:4.1.48-7+deb12u2vulnerable
trixie (security), trixie1:4.1.48-10+deb13u1vulnerable
forky, sid1:4.1.48-16vulnerable

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
nettysource(unstable)(unfixed)1148396

Notes

https://bugzilla.redhat.com/show_bug.cgi?id=2536976
https://github.com/netty/netty/security/advisories/GHSA-pq4x-537v-r54q

Search for package or bug name: Reporting problems