Not ratedCVE-2026-120634

    CGI: Exposure of Data Element to Wrong Session (CVE-2026-120634)

    Published Last modified Sources: CVE.org

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    What is affected, what to do

    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.

    Update CGI to version 5.00.

    Affected
    • CGI lt *..5.00
    Fixed in
    • CGI 5.00

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    Metrics

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    Priority

    No value is available for this vulnerability.

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    CVSS v3

    No value is available for this vulnerability.

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    EPSS score

    No value is available for this vulnerability.

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    Severity
    Not rated
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    30.00 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-488

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    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.

    Source: NVD (NIST), cvelistv5

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    —CGI
    • < 5.00
    • 5.00

    Weakness classes (CWE)

    • CWE-488Exposure of Data Element to Wrong Session

      Base

      The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.

      Entry at MITRE CWE-488

    References & sources

    • github.comleejo/CGI.pm/commit/604a83fec105f75fe06f1a75026c4c34fd5a1f61.pa…Patch
    • metacpan.orgrelease/LEEJO/CGI-4.72/source/lib/CGI/Carp.pmTechnical description
    • metacpan.orgrelease/LEEJO/CGI-5.00/changesRelease notes

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. ReceivedCPANSec

      Weakness type: CWE-488

      Description added or changed

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      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.
      Weakness type (CWE)added
      —
      CWE-488
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/120xxx/CVE-2026-120634.json">CVE-2026-120634</a>
      Referenceadded
      —
      https://github.com/leejo/CGI.pm/commit/604a83fec105f75fe06f1a75026c4c34fd5a1f61.patch
      Referenceadded
      —
      https://metacpan.org/release/LEEJO/CGI-4.72/source/lib/CGI/Carp.pm
      Referenceadded
      —
      https://metacpan.org/release/LEEJO/CGI-5.00/changes

      Source identifier: 9b29abf9-4ab0-4765-b253-1875cd9b441e

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