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.
{
"cna_assigner": "CPANSec",
"cwe_ids": [
"CWE-680"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8376.json"
}{
"cpe": "cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "0"
},
{
"last_affected": "5.43.10"
}
],
"source": [
"CPE_RANGE",
"REFERENCES"
]
}