CVE-2026-120634

CGI::Carp versions before 5.00 for Perl leak warnings across requests in persistent environments via the warningsToBrowser buffer

Published Nov 3, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
CGI::Carp versions before 5.00 for Perl leak warnings across requests in persistent environments via the warningsToBrowser buffer.

Warnings are held in a package-level buffer until warningsToBrowser writes them into the page as HTML comments, and the buffer is never cleared between requests. Under mod_perl, FastCGI or PSGI, warnings from one request are written into a later one.

Warnings that contain one user's request data can appear in the HTML sent to another user.

Remediation

Vendor Solution

Upgrade to CGI 5.00 or later.


Vendor Workaround

For deployments that cannot upgrade, do not use warningsToBrowser in persistent environments. After upgrading, persistent applications where nothing calls CGI::initialize_globals between requests must also call CGI::Carp::_reset_globals at the start of each request.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'}

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}

threat_severity

Moderate

Type Values Removed Values Added
Description CGI::Carp versions before 5.00 for Perl leak warnings across requests in persistent environments via the warningsToBrowser buffer. Warnings are held in a package-level buffer until warningsToBrowser writes them into the page as HTML comments, and the buffer is never cleared between requests. Under mod_perl, FastCGI or PSGI, warnings from one request are written into a later one. Warnings that contain one user's request data can appear in the HTML sent to another user.
Title CGI::Carp versions before 5.00 for Perl leak warnings across requests in persistent environments via the warningsToBrowser buffer
Weaknesses CWE-488
References

Subscriptions

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Weaknesses

Sources

Status
PUBLISHED
Assigner
CPANSec
Published
Updated
Nov 9, 2026, 7:06 PM
Reserved
Nov 2, 2026, 5:40 PM
Status
Deferred
Published
Nov 4, 2026, 12:17 AM
Modified
Nov 9, 2026, 7:16 PM
Severity
Moderate
Public date
Nov 3, 2026, 11:40 PM