CVE-2026-19487: Perl versions from 5.9.4 before 5.41.9 produce incorrect regular expression match results when a stale failure flag ends the Aho-Corasick prescan early in S_find_byclass

Overview

Severity

Medium (CVSS 5.3)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Exploit Status

Not Exploited

Patch Tuesday

2026-Aug

Released

2026-08-23

Last Updated

2026-09-10

EPSS Score

0.42% (percentile: 34.1%)

Affected Products (2)

Other

• 21697-17084
• 21848-17084

Security Updates (1)

• Security Update

Revision History

• 2026-08-23: Information published.
• 2026-09-09: Information published.
• 2026-09-10: Information published.