CVE-2026-8376

Name	CVE-2026-8376
Description	Perl versions through 5.43.10 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds. Perl_study_chunk in regcomp_study.c checked the size of the joined substring buffer in characters rather than bytes. For a quantified fixed substring with a large minimum count, the byte length mincount * l could overflow SSize_t, producing an undersized SvGROW allocation; the subsequent copy writes past the end of the buffer. A caller that compiles an attacker-controlled regular expression on a 32-bit perl build triggers a heap buffer overflow at compile time.
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	1137345

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
perl (PTS)	bullseye	5.32.1-4+deb11u3	vulnerable
	bullseye (security)	5.32.1-4+deb11u5	vulnerable
	bookworm	5.36.0-7+deb12u3	vulnerable
	bookworm (security)	5.36.0-7+deb12u2	vulnerable
	trixie	5.40.1-6	vulnerable
	forky	5.40.1-7	vulnerable
	sid	5.40.1-8	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
perl	source	(unstable)	5.40.1-8			1137345

Notes

[trixie] - perl <no-dsa> (Minor issue; can be fixed in point release)
[bookworm] - perl <no-dsa> (Minor issue; can be fixed in point release)
[bullseye] - perl <postponed> (Minor issue; can be fixed in point release)
https://github.com/Perl/perl5/pull/24433
https://lists.security.metacpan.org/cve-announce/msg/40396161/