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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-15534
StatePUBLISHED
AssignerCPANSec
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-09 18:16:42 UTC
Updated2026-08-09 22:16:30 UTC
DescriptionPerl 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. The 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. A caller that matches an attacker controlled subject of this size against a pattern of this shape can crash the process or corrupt heap memory.

Risk And Classification

Problem Types: CWE-125 | CWE-190 | CWE-787 | CWE-190 CWE-190 Integer Overflow or Wraparound | CWE-125 CWE-125 Out-of-bounds Read | CWE-787 CWE-787 Out-of-bounds Write

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA LEONT Perl affected 5.45.1 custom Not specified

References

ReferenceSourceLinkTags
github.com/Perl/perl5/commit/568e6fd238867bb9e99fa3f47cba3169009239e0.patch 9b29abf9-4ab0-4765-b253-1875cd9b441e github.com
www.openwall.com/lists/oss-security/2026/08/09/13 af854a3a-2127-422b-91ae-364da2661108 www.openwall.com
www.openwall.com/lists/oss-security/2026/08/09/12 af854a3a-2127-422b-91ae-364da2661108 www.openwall.com
github.com/Perl/perl5/commit/54cf3d44cbbedd17d774e9a37921963e8fd5d0cb.patch 9b29abf9-4ab0-4765-b253-1875cd9b441e github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

Solutions

CNA: Upgrade to a future Perl release, or apply the upstream patches.

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report