CVE catalog
CVE-2026-15534
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. The regex engine's superlinear cache holds
- Severity
- Medium · CVSS 5.7
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.26% · Oct 23, 2026
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. 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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | perl | sid | 5.42.3-1 | vulnerable |
| Debian | perl | forky | 5.42.3-1 | vulnerable |
| Debian | perl | trixie | 5.40.1-6+deb13u1 | vulnerable |
| Debian | perl | bookworm | 5.36.0-7+deb12u3 | vulnerable |
| Debian | perl | bookworm-security | 5.36.0-7+deb12u4 | vulnerable |
| Ubuntu | perl | noble | 5.38.2-3.2ubuntu0.6 | fixed |
| Ubuntu | libperl-dev | noble | 5.38.2-3.2ubuntu0.6 | fixed |
| Ubuntu | libperl5.38t64 | noble | 5.38.2-3.2ubuntu0.6 | fixed |
| Ubuntu | perl-base | noble | 5.38.2-3.2ubuntu0.6 | fixed |
| Ubuntu | perl-debug | noble | 5.38.2-3.2ubuntu0.6 | fixed |
| Ubuntu | perl-doc | noble | 5.38.2-3.2ubuntu0.6 | fixed |
| Ubuntu | perl-modules-5.38 | noble | 5.38.2-3.2ubuntu0.6 | fixed |
| Ubuntu | perl | 24.04 | 5.36.0-9ubuntu1 | vulnerable |
| Ubuntu | perl | 24.04 | 5.36.0-10ubuntu1 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3.2 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3.2build1 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3.2build2 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3.2build2.1 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3.2ubuntu0.1 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3.2ubuntu0.2 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3.2ubuntu0.3 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3.2ubuntu0.4 | vulnerable |
| Ubuntu | perl | 24.04 | 5.38.2-3.2ubuntu0.6 | fixed |
| Ubuntu | perl | pro | 5.28.1-6build1 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-7 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-9 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-9build1 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-9ubuntu0.2 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-9ubuntu0.3 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-9ubuntu0.4 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-9ubuntu0.5 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-9ubuntu0.5+esm2 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-9ubuntu0.5+esm3 | vulnerable |
| Ubuntu | perl | pro | 5.30.0-9ubuntu0.5+esm4 | fixed |
| Ubuntu | perl | 22.04 | 5.32.1-3ubuntu3 | vulnerable |
| Ubuntu | perl | 22.04 | 5.34.0-3ubuntu1 | vulnerable |
| Ubuntu | perl | 22.04 | 5.34.0-3ubuntu1.1 | vulnerable |
| Ubuntu | perl | 22.04 | 5.34.0-3ubuntu1.2 | vulnerable |
| Ubuntu | perl | 22.04 | 5.34.0-3ubuntu1.3 | vulnerable |
| Ubuntu | perl | 22.04 | 5.34.0-3ubuntu1.4 | vulnerable |
| Ubuntu | perl | 22.04 | 5.34.0-3ubuntu1.5 | vulnerable |
| Ubuntu | perl | 22.04 | 5.34.0-3ubuntu1.7 | vulnerable |
| Ubuntu | perl | 22.04 | 5.34.0-3ubuntu1.8 | vulnerable |
| Ubuntu | perl | 22.04 | 5.34.0-3ubuntu1.9 | fixed |
| Ubuntu | perl | 26.04 | 5.40.1-6build1 | vulnerable |
| Ubuntu | perl | 26.04 | 5.40.1-7build1 | vulnerable |
| Ubuntu | perl | 26.04 | 5.40.1-7ubuntu0.1 | vulnerable |
| Ubuntu | perl | 26.04 | 5.40.1-7ubuntu0.2 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | perl | source | sid | (unfixed) | not yet assigned | Not reported | [1144413] |
| Debian | perl | source | forky | (unfixed) | not yet assigned | Not reported | [1144413] |
| Debian | perl | source | trixie | (unfixed) | not yet assigned | Not reported | [1144413] |
| Debian | perl | source | bookworm | (unfixed) | not yet assigned | Not reported | [1144413] |
| Ubuntu | perl | deb | noble | 5.38.2-3.2ubuntu0.6 | Not reported | Not reported | Not reported |
| Ubuntu | libperl-dev | deb | noble | 5.38.2-3.2ubuntu0.6 | Not reported | Not reported | Not reported |
| Ubuntu | libperl5.38t64 | deb | noble | 5.38.2-3.2ubuntu0.6 | Not reported | Not reported | Not reported |
| Ubuntu | perl-base | deb | noble | 5.38.2-3.2ubuntu0.6 | Not reported | Not reported | Not reported |
| Ubuntu | perl-debug | deb | noble | 5.38.2-3.2ubuntu0.6 | Not reported | Not reported | Not reported |
| Ubuntu | perl-doc | deb | noble | 5.38.2-3.2ubuntu0.6 | Not reported | Not reported | Not reported |
| Ubuntu | perl-modules-5.38 | deb | noble | 5.38.2-3.2ubuntu0.6 | Not reported | Not reported | Not reported |
| Ubuntu | perl | deb | 24.04 | 5.38.2-3.2ubuntu0.6 | Not reported | USN-8736-2 | Not reported |
| Ubuntu | perl | deb | pro | 5.30.0-9ubuntu0.5+esm4 | Not reported | USN-8736-1 | Not reported |
| Ubuntu | perl | deb | 22.04 | 5.34.0-3ubuntu1.9 | Not reported | USN-8736-1 | Not reported |
| Ubuntu | perl | deb | 26.04 | 5.40.1-7ubuntu0.2 | Not reported | USN-8736-1 | Not reported |
Notes
[trixie] perl: Wait for exposure unstable and coordinate with Perl maintainers
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libperl5.36]Affected
Source package: [perl]
Details (4)
5.36.0-7+deb12u3· amd64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u3· arm64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· amd64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· arm64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
- [libperl-dev]Affected
Source package: [perl]
Details (4)
5.36.0-7+deb12u3· amd64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u3· arm64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· amd64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· arm64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
- [perl]Affected
Details (4)
5.36.0-7+deb12u3· amd64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u3· arm64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· amd64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· arm64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
- [perl-base]Affected
Source package: [perl]
Details (4)
5.36.0-7+deb12u3· amd64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u3· arm64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· amd64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· arm64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
- [perl-debug]Affected
Source package: [perl]
Details (4)
5.36.0-7+deb12u3· amd64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u3· arm64 · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· amd64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· arm64 · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
- [perl-doc]Affected
Source package: [perl]
Details (4)
5.36.0-7+deb12u3· all · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u3· all · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· all · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· all · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
- [perl-modules-5.36]Affected
Source package: [perl]
Details (4)
5.36.0-7+deb12u3· all · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u3· all · bookwormAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· all · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
5.36.0-7+deb12u2· all · bookworm-securityAffected
nvd · perl · debian · bookworm; nvd · perl · debian · 12
[Debian 13 (Trixie)]
- [libperl5.40]Affected
Source package: [perl]
Details (2)
5.40.1-6· amd64 · trixieAffected
nvd · perl · debian · 13
5.40.1-6· arm64 · trixieAffected
nvd · perl · debian · 13
- [libperl-dev]Affected
Source package: [perl]
Details (2)
5.40.1-6· amd64 · trixieAffected
nvd · perl · debian · 13
5.40.1-6· arm64 · trixieAffected
nvd · perl · debian · 13
- [perl]Affected
Details (2)
5.40.1-6· amd64 · trixieAffected
nvd · perl · debian · 13
5.40.1-6· arm64 · trixieAffected
nvd · perl · debian · 13
- [perl-base]Affected
Source package: [perl]
Details (2)
5.40.1-6· amd64 · trixieAffected
nvd · perl · debian · 13
5.40.1-6· arm64 · trixieAffected
nvd · perl · debian · 13
- [perl-debug]Affected
Source package: [perl]
Details (2)
5.40.1-6· amd64 · trixieAffected
nvd · perl · debian · 13
5.40.1-6· arm64 · trixieAffected
nvd · perl · debian · 13
- [perl-doc]Affected
Source package: [perl]
Details (2)
5.40.1-6· all · trixieAffected
nvd · perl · debian · 13
5.40.1-6· all · trixieAffected
nvd · perl · debian · 13
- [perl-modules-5.40]Affected
Source package: [perl]
Details (2)
5.40.1-6· all · trixieAffected
nvd · perl · debian · 13
5.40.1-6· all · trixieAffected
nvd · perl · debian · 13
Observed:
References
- [http://www.openwall.com/lists/oss-security/2026/08/09/12]
- [http://www.openwall.com/lists/oss-security/2026/08/09/13]
- [https://access.redhat.com/errata/RHSA-2026:63403]
- [https://github.com/Perl/perl5/commit/54cf3d44cbbedd17d774e9a37921963e8fd5d0cb.patch]
- [https://github.com/Perl/perl5/commit/568e6fd238867bb9e99fa3f47cba3169009239e0.patch]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-15534]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-15534]
- [https://osv.dev/vulnerability/USN-8736-1]
- [https://osv.dev/vulnerability/USN-8736-2]
- [https://security-tracker.debian.org/tracker/CVE-2026-15534]
- [https://ubuntu.com/security/notices/USN-8736-2]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2717.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [Ubuntu Security Notices (USN)]