When such branches are combined into a trie, the delta between the first branch and the shared tail is stored in a 16-bit field. A branch count above 65535 overflows the field, and the trie's match decision table is truncated with no warning or error.
A pattern of this shape produces false positive matches (matching strings it should not) and false negative matches (failing to match strings it should). When such a pattern gates an access or filtering decision, the result is wrong.
| Source | ID | Title |
|---|---|---|
Ubuntu USN |
USN-8684-1 | Perl vulnerabilities |
Solution
Apply the upstream patch. The fix is included in the Perl 5.43.10 development release.
Workaround
No workaround given by the vendor.
Tue, 14 Jul 2026 14:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
cvssV3_1
|
Mon, 13 Jul 2026 18:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Shay
Shay perl |
|
| Vendors & Products |
Shay
Shay perl |
Mon, 13 Jul 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Perl versions through 5.43.9 produce silently incorrect regular expression matches when an alternation of more than 65535 fixed string branches is compiled into a trie in Perl_study_chunk. When such branches are combined into a trie, the delta between the first branch and the shared tail is stored in a 16-bit field. A branch count above 65535 overflows the field, and the trie's match decision table is truncated with no warning or error. A pattern of this shape produces false positive matches (matching strings it should not) and false negative matches (failing to match strings it should). When such a pattern gates an access or filtering decision, the result is wrong. | |
| Title | Perl versions through 5.43.9 produce silently incorrect regular expression matches when an alternation of more than 65535 fixed string branches is compiled into a trie in Perl_study_chunk | |
| Weaknesses | CWE-190 | |
| References |
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: CPANSec
Published:
Updated: 2026-07-14T13:33:18.189Z
Reserved: 2026-06-24T15:38:41.010Z
Link: CVE-2026-13221
Updated: 2026-07-13T19:30:45.640Z
Status : Analyzed
Published: 2026-07-13T17:16:48.923
Modified: 2026-07-14T18:15:18.850
Link: CVE-2026-13221
No data.
OpenCVE Enrichment
Updated: 2026-08-01T10:15:03Z
Ubuntu USN