Vulnerability-Lookup

GHSA-2P7F-7XJF-8Q9Q

Vulnerability from github – Published: 2026-02-27 21:31 – Updated: 2026-03-03 21:31

Details

HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function.

The HTTP::Session2 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.

HTTP::Session2 after version 1.02 will attempt to use the /dev/urandom device to generate a session id, but if the device is unavailable (for example, under Windows), then it will revert to the insecure method described above.

Severity

6.5 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-3255"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-338"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-02-27T20:21:41Z",
    "severity": "MODERATE"
  },
  "details": "HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function.\n\nThe HTTP::Session2 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\nHTTP::Session2 after version 1.02 will attempt to use the /dev/urandom device to generate a session id, but if the device is unavailable (for example, under Windows), then it will revert to the insecure method described above.",
  "id": "GHSA-2p7f-7xjf-8q9q",
  "modified": "2026-03-03T21:31:10Z",
  "published": "2026-02-27T21:31:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-3255"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tokuhirom/HTTP-Session2/commit/9cfde4d7e0965172aef5dcfa3b03bb48df93e636.patch"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.01/source/lib/HTTP/Session2/ServerStore.pm#L68"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.11/source/lib/HTTP/Session2/Random.pm#L35"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.12/changes"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/02/27/12"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-3255 (GCVE-0-2026-3255)

Vulnerability from cvelistv5 – Published: 2026-02-27 20:12 – Updated: 2026-03-03 20:23

Title

HTTP::Session2 versions before 1.12 for Perl may generate weak session ids using the rand() function

Summary

HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function. The HTTP::Session2 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. HTTP::Session2 after version 1.02 will attempt to use the /dev/urandom device to generate a session id, but if the device is unavailable (for example, under Windows), then it will revert to the insecure method described above.

Severity

6.5 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-03 20:23 UTC

CWE

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

Assigner

CPANSec CNA under the redhat root

CNA scorecard C 64/100 over 265 records in the last 180 days details

References

5 references

URL	Tags
https://metacpan.org/release/TOKUHIROM/HTTP-Sessi…
https://metacpan.org/release/TOKUHIROM/HTTP-Sessi…
https://metacpan.org/release/TOKUHIROM/HTTP-Sessi…	release-notes
https://github.com/tokuhirom/HTTP-Session2/commit…	patch
http://www.openwall.com/lists/oss-security/2026/0…

Impacted products

1 product

Vendor	Product	Version
TOKUHIROM	HTTP::Session2	Affected: 0 , < 1.12 (custom)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-02-28T00:15:39.689Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/02/27/12"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "LOW",
              "baseScore": 6.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-3255",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-03T20:23:27.914632Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-03T20:23:53.160Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "packageName": "HTTP-Session2",
          "product": "HTTP::Session2",
          "repo": "https://github.com/tokuhirom/HTTP-Session2",
          "vendor": "TOKUHIROM",
          "versions": [
            {
              "lessThan": "1.12",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function.\n\nThe HTTP::Session2 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\nHTTP::Session2 after version 1.02 will attempt to use the /dev/urandom device to generate a session id, but if the device is unavailable (for example, under Windows), then it will revert to the insecure method described above."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-115",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-115 Authentication Bypass"
            }
          ]
        }
      ],
      "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": "2026-02-27T20:12:35.414Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "url": "https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.11/source/lib/HTTP/Session2/Random.pm#L35"
        },
        {
          "url": "https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.01/source/lib/HTTP/Session2/ServerStore.pm#L68"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.12/changes"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/tokuhirom/HTTP-Session2/commit/9cfde4d7e0965172aef5dcfa3b03bb48df93e636.patch"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "HTTP::Session2 has been deprecated since version 1.11. Migrate to a different solution."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "timeline": [
        {
          "lang": "en",
          "time": "2014-07-31T00:00:00.000Z",
          "value": "version 1.02 HTTP::Session2 released that attempts to use /dev/urandom."
        },
        {
          "lang": "en",
          "time": "2026-02-24T00:00:00.000Z",
          "value": "version 1.11 HTTP::Session2 deprecated"
        },
        {
          "lang": "en",
          "time": "2026-02-26T00:00:00.000Z",
          "value": "version 1.12 HTTP::Session2 released with a fix with a portable solution."
        }
      ],
      "title": "HTTP::Session2 versions before 1.12 for Perl may generate weak session ids using the rand() function",
      "workarounds": [
        {
          "lang": "en",
          "value": "Upgrade to version 1.12 or later."
        }
      ],
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-3255",
    "datePublished": "2026-02-27T20:12:35.414Z",
    "dateReserved": "2026-02-26T11:43:17.278Z",
    "dateUpdated": "2026-03-03T20:23:53.160Z",
    "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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

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