CVE-2026-13051

CVE-2026-13051

Form::Processor::Field::HtmlArea versions from 0.06 through 1.162360 for Perl allow attacker selected method dispatch and resource exhaustion via an HTML::Tidy diagnostic that validate passes to add_error as a Locale::Maketext template. validate runs HTML::Tidy over the submitted markup and passes each resulting message to add_error as its first argument, which add_error hands to the language handle as the Locale::Maketext message key. The default handle's lexicon sets `_AUTO`, so a message that is not a lexicon entry is compiled as a bracket notation template instead of being looked up. Tidy diagnostics quote the offending attribute name or value, so a bracket group in the submitted markup reaches the template position, where the first token of the group names a method called on the language handle and the remaining tokens are its arguments. A group such as `[0]` makes the compile croak, and neither the field nor the handle catches it, so the exception leaves validate. `[sprintf,%2000000000d,7]` reaches CORE::sprintf with an attacker chosen field width. One submission of crafted markup to an HtmlArea field throws an unhandled exception out of form validation or allocates an arbitrary amount of memory, and an application whose language handle subclass defines side effecting public methods makes those callable with attacker chosen arguments. The other field types pass fixed templates with the submitted value in an argument slot, where it stays inert, and are unaffected.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.006 (44.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-13051: held from 0.005 to 0.006.

EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-13051?
CVE-2026-13051 is a critical-severity vulnerability, classified under Use of Externally-Controlled Input to Select Classes or Code (Unsafe Reflection). CVSS score: 9.1/10. Published 2026-08-13.
How severe is CVE-2026-13051?
Critical severity. CVSS v3 base score is 9.1 out of 10.