CVE-2026-19873
HTML::FormFu versions through 2.08 for Perl allow resource exhaustion via an unbounded repeat count from the query string in Repeatable elements
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
HTML::FormFu versions through 2.08 for Perl allow resource exhaustion via an unbounded repeat count from the query string in Repeatable elements
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.
- Record
CVE-2026-19873- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1284, CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2026-68458
7.5
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.
- Record
EUVD-2026-68458- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-8cjx-f34x-86x3
7.5
HTML::FormFu versions through 2.08 for Perl allow resource exhaustion via an unbounded repeat...
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.
- Record
GHSA-8cjx-f34x-86x3- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2026-19873- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770, CWE-1284
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-19873
7.5
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.
- Record
DEBIAN-CVE-2026-19873- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-19873
7.5
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.
- Record
UBUNTU-CVE-2026-19873- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVMGASA-2026-0404 No score
Updated perl-HTML-FormFu packages fix a security vulnerability
HTML::FormFu versions through 2.08 for Perl allow resource exhaustion via an unbounded repeat count from the query string in Repeatable elements. (CVE-2026-19873)
- Record
MGASA-2026-0404- Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libhtml-formfu-perlDebian:12 |
All versions, plus listed versions 2.07000-12.07000-22.07000-3 |
None known |
libhtml-formfu-perlDebian:13 |
All versions, plus listed versions 2.07000-22.07000-3 |
None known |
libhtml-formfu-perlDebian:14 |
before 2.07000-3, plus listed versions 2.07000-2 |
2.07000-3 |
perl-HTML-FormFuMageia:10 |
before 2.60.0-5.1.mga10 | 2.60.0-5.1.mga10 |
perl-HTML-FormFuMageia:9 |
before 2.60.0-4.1.mga9 | 2.60.0-4.1.mga9 |
libhtml-formfu-perlUbuntu:16.04:LTS |
All versions, plus listed versions 2.01000-2 |
None known |
libhtml-formfu-perlUbuntu:18.04:LTS |
All versions, plus listed versions 2.05000-1 |
None known |
libhtml-formfu-perlUbuntu:20.04:LTS |
All versions, plus listed versions 2.07000-1 |
None known |
libhtml-formfu-perlUbuntu:22.04:LTS |
All versions, plus listed versions 2.07000-1 |
None known |
libhtml-formfu-perlUbuntu:24.04:LTS |
All versions, plus listed versions 2.07000-1 |
None known |
libhtml-formfu-perlUbuntu:26.10 |
All versions, plus listed versions 2.07000-2 |
None known |
libhtml-formfu-perlUbuntu:26.04:LTS |
All versions, plus listed versions 2.07000-2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-19873 is a high vulnerability (CVSS 7.5) in libhtml-formfu-perl, published August 31, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.52%, the 44th percentile. Fixed in libhtml-formfu-perl 2.07000-3.