USN-8736-1: Perl vulnerabilities
Ubuntu issued USN-8736-1 fixing two Perl regex flaws that could cause denial of service, code execution, or security-restriction bypass.
Ubuntu released a security notice addressing two Perl vulnerabilities in regular expression handling. CVE-2026-15534 involves mishandling of large inputs during regex matching, enabling out-of-bounds heap reads or writes that could lead to denial of service or arbitrary code execution. CVE-2026-19487 involves incorrect matching for regexes with alternative branches, allowing security restrictions to be bypassed. Users are advised to apply the updated packages.
- Perl regex flaw allows out-of-bounds heap reads/writes, potentially enabling code execution
- Second flaw lets crafted regexes with alternative branches bypass security restrictions
- Fixed in updated Ubuntu packages under USN-8736-1
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
| 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 | 5.7 | <1% | ||
| CVE-2026-19487 | Perl regex engine flaw yields incorrect match results via stale failure flag | 5.3 | <1% |
From the original article
It was discovered that Perl incorrectly handled certain large inputs during regular expression matching. An attacker could possibly use this issue to trigger out-of-bounds heap reads or writes, resulting in a denial of service or arbitrary code execution. (CVE-2026-15534) It was discovered that Perl incorrectly handled certain regular expression containing alternative matching branches.
ubuntu.com
A short excerpt; the article and its images belong to the publisher. Summary, key facts and assessment above are AI-written from the article and can be wrong.