Vulnerability-Lookup

GHSA-G98H-C5V8-8M3F

Vulnerability from github – Published: 2026-03-05 03:31 – Updated: 2026-03-12 00:31

Details

Plack::Middleware::Session::Simple versions through 0.04 for Perl generates session ids insecurely.

The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.

Predicable session ids could allow an attacker to gain access to systems.

Plack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923.

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2025-40926"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-338"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-05T02:16:39Z",
    "severity": "CRITICAL"
  },
  "details": "Plack::Middleware::Session::Simple versions through 0.04 for Perl generates session ids insecurely.\n\nThe default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.\n\nPredicable session ids could allow an attacker to gain access to systems.\n\nPlack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923.",
  "id": "GHSA-g98h-c5v8-8m3f",
  "modified": "2026-03-12T00:31:15Z",
  "published": "2026-03-05T03:31:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40926"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kazeburo/Plack-Middleware-Session-Simple/pull/4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kazeburo/Plack-Middleware-Session-Simple/commit/760bb358b8f53e52cf415888a4ac858fd99bb24e.patch"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.04/source/lib/Plack/Middleware/Session/Simple.pm#L43"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.05/changes"
    },
    {
      "type": "WEB",
      "url": "https://security.metacpan.org/docs/guides/random-data-for-security.html"
    },
    {
      "type": "WEB",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-40923"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2025-40926 (GCVE-0-2025-40926)

Vulnerability from cvelistv5 – Published: 2026-03-05 01:24 – Updated: 2026-04-21 02:42

Title

Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely

Summary

Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely. The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predictable session ids could allow an attacker to gain access to systems. Plack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923.

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-05 16:28 UTC

CWE

CWE-340 - Generation of Predictable Numbers or Identifiers
CWE-338 - Use of Cryptographically Weak Pseudo-Random Number Generator

Assigner

CPANSec redhat root

References

6 references

URL	Tags
https://metacpan.org/release/KAZEBURO/Plack-Middl…
https://github.com/kazeburo/Plack-Middleware-Sess…	issue-tracking
https://github.com/kazeburo/Plack-Middleware-Sess…	patch
https://www.cve.org/CVERecord?id=CVE-2025-40923	vendor-advisoryrelatedvdb-entry
https://security.metacpan.org/docs/guides/random-…	technical-description
https://metacpan.org/release/KAZEBURO/Plack-Middl…	release-notes

Impacted products

1 product

Vendor	Product	Version
KAZEBURO	Plack::Middleware::Session::Simple	Affected: 0 , < 0.05 (custom)

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.8,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2025-40926",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-05T16:28:14.069463Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-21T02:42:17.296Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "packageName": "Plack-Middleware-Session-Simple",
          "product": "Plack::Middleware::Session::Simple",
          "programFiles": [
            "lib/Plack/Middleware/Session/Simple.pm"
          ],
          "programRoutines": [
            {
              "name": "Plack::Middleware::Session::Simple::sid_generator"
            }
          ],
          "repo": "https://github.com/kazeburo/Plack-Middleware-Session-Simple",
          "vendor": "KAZEBURO",
          "versions": [
            {
              "lessThan": "0.05",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely.\n\nThe default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.\n\nPredictable session ids could allow an attacker to gain access to systems.\n\nPlack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-340",
              "description": "CWE-340 Generation of Predictable Numbers or Identifiers",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-338",
              "description": "CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-11T23:25:24.779Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "url": "https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.04/source/lib/Plack/Middleware/Session/Simple.pm#L43"
        },
        {
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/kazeburo/Plack-Middleware-Session-Simple/pull/4"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/kazeburo/Plack-Middleware-Session-Simple/commit/760bb358b8f53e52cf415888a4ac858fd99bb24e.patch"
        },
        {
          "tags": [
            "vendor-advisory",
            "related",
            "vdb-entry"
          ],
          "url": "https://www.cve.org/CVERecord?id=CVE-2025-40923"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://security.metacpan.org/docs/guides/random-data-for-security.html"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.05/changes"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Users are advised to upgrade to version 0.05 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely",
      "workarounds": [
        {
          "lang": "en",
          "value": "Users are advised to change the sid_generator attribute of Plack::Middleware::Session::Simple to a function that returns a securely generated session id based on a secure source of entropy from the system.\n\nUsers may consider using Plack::Middleware::Session version 0.35 or later."
        }
      ],
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2025-40926",
    "datePublished": "2026-03-05T01:24:34.151Z",
    "dateReserved": "2025-04-16T09:05:34.362Z",
    "dateUpdated": "2026-04-21T02:42:17.296Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-G98H-C5V8-8M3F

CVE-2025-40926 (GCVE-0-2025-40926)

Tags

Sightings

Nomenclature

Related by attack behaviour