{"cve":"CVE-2026-15534","nvd":{"published":"2026-08-09T18:16:42.800","modified":"2026-10-23T20:10:00.160","status":"Awaiting Analysis","description":"Perl versions through 5.45.1 have out-of-bounds heap reads and writes during regular expression matching via an undersized superlinear cache in S_regmatch.\n\nThe regex engine's superlinear cache holds one bit per subject position for each participating WHILEM node, so the bit count is the subject length plus one times the number of nodes. Nothing checks that product for positive overflow of the signed 32-bit count: a 286331153 byte subject matched against a pattern with 15 participating nodes stores the count as 14, leaving a two byte cache. The cache is then indexed from the real match position and node number, so reads go past the end of the allocation, and on failure CACHEsayNO sets a bit past it.\n\nA caller that matches an attacker controlled subject of this size against a pattern of this shape can crash the process or corrupt heap memory.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","score":5.7},"cwes":["CWE-125","CWE-190","CWE-787"],"references":["https://github.com/Perl/perl5/commit/54cf3d44cbbedd17d774e9a37921963e8fd5d0cb.patch","https://github.com/Perl/perl5/commit/568e6fd238867bb9e99fa3f47cba3169009239e0.patch","http://www.openwall.com/lists/oss-security/2026/08/09/12","http://www.openwall.com/lists/oss-security/2026/08/09/13"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:34.184483516+00:00"},"epss":{"cve":"CVE-2026-15534","score":0.00164,"percentile":0.05595,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}