Paper/Archive/CVE-2026-8376

CVE-2026-8376

CPANSec — Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.11 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds

Description · from the CVE record

Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.11 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.

Affected

ProductAffectedFixed inSource
perl< 5.40.5-RC15.40.5-RC1CNA
perl5.41.0 – < 5.42.3-RC15.42.3-RC1CNA
perl5.43.0 – < 5.43.115.43.11CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADP7.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: partial

References

patchgithub.com/Perl/perl5/commit/5e7f119eb2bb1181be908701f22bf7068e722f1c.patchrefopenwall.com/lists/oss-security/2026/05/26/1