When a Repeatable element has counter_name set, its process method reads the repeat count from the named query string parameter, checks only that it is a positive integer, and passes it to repeat, which deep-clones the element's child subtree once per iteration. Nothing caps the value, and no attribute lets an application impose a limit.
The count is read on every request, before the form decides whether it was submitted, so a plain GET reaches the clone loop with no credentials, no session and no request body. Nesting multiplies: a Repeatable inside a Repeatable takes a counter at each level, so an outer and an inner value of 100 build 10,000 clones.
Once the form is submitted, each cloned field's constraints scan the whole element tree in _find_field_value, so cost grows faster than linearly with the count. A single request exhausts memory and CPU.
The latest release on CPAN is 2.07, from 2018. Version 2.08 exists only in the git repository.
Metrics
Affected Vendors & Products
No advisories yet.
Solution
Apply the patch. There is no fixed release.
Workaround
For deployments that cannot apply the patch, reject or clamp the counter parameter before passing the query to process. Where the client-side repeat feature is not needed, unsetting counter_name stops the count being read from the query string.
Mon, 31 Aug 2026 10:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | HTML::FormFu versions through 2.08 for Perl allow resource exhaustion via an unbounded repeat count from the query string in Repeatable elements. When a Repeatable element has counter_name set, its process method reads the repeat count from the named query string parameter, checks only that it is a positive integer, and passes it to repeat, which deep-clones the element's child subtree once per iteration. Nothing caps the value, and no attribute lets an application impose a limit. The count is read on every request, before the form decides whether it was submitted, so a plain GET reaches the clone loop with no credentials, no session and no request body. Nesting multiplies: a Repeatable inside a Repeatable takes a counter at each level, so an outer and an inner value of 100 build 10,000 clones. Once the form is submitted, each cloned field's constraints scan the whole element tree in _find_field_value, so cost grows faster than linearly with the count. A single request exhausts memory and CPU. The latest release on CPAN is 2.07, from 2018. Version 2.08 exists only in the git repository. | |
| Title | HTML::FormFu versions through 2.08 for Perl allow resource exhaustion via an unbounded repeat count from the query string in Repeatable elements | |
| Weaknesses | CWE-1284 CWE-770 |
|
| References |
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: CPANSec
Published:
Updated: 2026-08-31T12:11:31.961Z
Reserved: 2026-08-14T12:57:36.382Z
Link: CVE-2026-19873
No data.
Status : Received
Published: 2026-08-31T10:16:49.790
Modified: 2026-08-31T10:16:49.790
Link: CVE-2026-19873
No data.
OpenCVE Enrichment
Updated: 2026-08-31T12:00:06Z