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CVE-2026-120634

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

Products / packages CGI

Published

Share

Severity and exploitation

Not in CISA KEV

KEV coverage does not rule out exploitation.

KEV checked 15/11/2026, 00:25:34 UTC
CISA-ADP · CVSS:3.1 · 6.5
Assessment vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Severity

medium6.5

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Not established by this record

Missing evidence does not mean no public exploit exists.

Remediation

Source guidance available

Review the recorded instructions. Guidance may be a workaround rather than a fixed version.

What this means

CGI::Carp versions before 5.00 for Perl leak warnings across requests in persistent environments, potentially exposing one user's request data to another. The warningsToBrowser buffer is not cleared between requests. This weakness can lead to exposure of data elements to wrong sessions.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Vendor not supplied · CPANSec

CGI

1 range
CPANSec version evidence

Package identity

pkg:cpan/CGI

Identity supplied by CPANSec. Version matching requires compatible range evidence.

Compare with this publisher’s ranges. This does not inspect your installation.

affected

0 → before 5.00

custom versions

unaffected

unknown

Other versions: unaffected

Automatic dependency matching is unavailable for this record. Use the product evidence and publisher’s instructions to check your installation.

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

Upgrade to CGI 5.00 or later.

CPANSec guidance ↗

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.

CPANSec guidance ↗

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.

Original source description

Read the full publisher 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.

References

3 sources
leejo/CGI.pm · commit 604a83f
PatchCPANSec
metacpan.org/release/LEEJO/CGI-4.72/source/lib/CGI/Carp.pm
Source referenceCPANSec
metacpan.org/release/LEEJO/CGI-5.00/changes
Source referenceCPANSec

Inside the record

Evidence available

Package identity
Version evidence
Remediation guidance
Weakness classification
Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-120634

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-488 ↗

CWE-488 Exposure of Data Element to Wrong Session

CPANSec

Related →
Contributing organizations · 2
CPANSec

Assigning organization

2026-11-03
CISA-ADP

Additional data publisher

2026-11-09

Timeline

All times UTC

  1. Advisory published

    Publication date supplied by the source.

  2. Source updated

    Latest modification date supplied by the source.

  3. Last imported by cve.new

    Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes
  1. CVE · CVE-2026-120634

    Observed 2026-11-09T19:34:58.278Z · upstream updated 2026-11-09T19:06:50.795Z

    Severity assessment changed

    before

    []

    after

    [
  {
    "source": "CISA-ADP",
    "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
    "score": 6.5
  }
]
    Prioritization updated

    before

    []

    after

    [
  {
    "source": "CISA-ADP",
    "type": "SSVC",
    "role": "CISA Coordinator",
    "timestamp": "2026-11-09T19:06:22.430750Z",
    "decisions": [
      {
        "name": "Exploitation",
        "value": "none"
      },
      {
        "name": "Automatable",
        "value": "no"
      },
      {
        "name": "Technical Impact",
        "value": "partial"
      }
    ]
  }
]

Large field values are marked as truncated previews. Original source snapshots remain retained.

Showing up to 50 most recent observed changes.