CVE-2026-19499

Name	CVE-2026-19499
Description	Calling strfmon and strfmon_l in the GNU C Library version 2.38 to 2.44 can write past the end of the caller-supplied output buffer when a conversion uses right-justified width padding. Exploitation requires an application code path that calls strfmon or strfmon_l with right-justified width padding into a destination buffer that is large enough for the padding to succeed but too small for the internal memmove call. The field width or format may be attacker-influenced or a fixed susceptible pattern in the caller. At the time of publication, no network-facing application impact is known.
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)
Debian Bugs	1145891

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
glibc (PTS)	bookworm	2.36-9+deb12u14	vulnerable
	bookworm (security)	2.36-9+deb12u7	vulnerable
	trixie	2.41-12+deb13u4	vulnerable
	forky, sid	2.43-5	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
glibc	source	(unstable)	2.43-5			1145891

Notes

[trixie] - glibc <no-dsa> (Minor issue)
[bookworm] - glibc <postponed> (Minor issue)
https://bugzilla.redhat.com/show_bug.cgi?id=2523258
https://sourceware.org/bugzilla/show_bug.cgi?id=34510
https://sourceware.org/git/?p=glibc.git;a=blob;f=advisories/GLIBC-SA-2026-0017