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.
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.
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.
Published:
2026-08-09
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| LEONT | perl | unaffected |
|
No data.
No data.
No data available yet.
Remediation
Vendor Solution
Upgrade to a future Perl release, or apply the upstream patches.
Tracking
Sign in to view the affected projects.
Advisories
No advisories yet.
References
History
Sun, 09 Aug 2026 18:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. 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. | |
| Title | 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 | |
| Weaknesses | CWE-125 CWE-190 CWE-787 |
|
| References |
|
Subscriptions
No data.
MITRE
Status: PUBLISHED
Assigner: CPANSec
Published:
Updated: 2026-08-09T22:07:56.263Z
Reserved: 2026-07-12T17:04:25.249Z
Link: CVE-2026-15534
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-08-09T19:30:04Z