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
Last updated 16 September 2026
Other sources
Perl versions through 5.45.1 have out-of-bounds heap reads and writes during regular expression matching via an undersized superlinear cache in Sregmatch
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 5.38.2-515 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 5.38.2-516 - Upgrade
Upgrade
Perlto a version that resolves this vulnerability.Fixed in 5.45.2 - Compensating control
Until patched, mitigate potential crashes/corruption by restricting or filtering attacker-controlled regex inputs that could match an attacker-controlled subject/pattern shape triggering the S_regmatch superlinear cache overflow.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-15534?
CVE-2026-15534 has a risk rating of 57.
How do I fix CVE-2026-15534?
To fix CVE-2026-15534, upgrade to Perl version 5.45.2 or later.
What causes the vulnerability in CVE-2026-15534?
CVE-2026-15534 is caused by out-of-bounds heap reads and writes during regular expression matching due to an undersized superlinear cache.
Which versions of Perl are affected by CVE-2026-15534?
Perl versions up to and including 5.45.1 are affected by CVE-2026-15534.
What is the impact of CVE-2026-15534?
The impact of CVE-2026-15534 can potentially lead to memory corruption and unpredictable behavior in applications using affected Perl versions.