CVE-2026-8376
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.
- Perl
- ≤ 5.43.10
- Fix
- Available
- CVSS 3.1
- 9.8 CRITICAL
- EPSS
- 0.4% (37th percentile)
- Weakness
- CWE-680
- NVD status
- Modified
- Published
- 2026-05-25
Fix
Upgrade to a future perl release, or apply the upstream patch.
Workaround
On 32-bit perl builds, avoid compiling regular expressions from untrusted input until a fixed release is installed.
1 known exploit for CVE-2026-8376
Proof-of-concept code and exploit modules indexed by Sploitus