Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids

{
  "id": "27ad4bc671c2ef5c1a68ee14d8752fe585776dda23bc2321482aba3491b94f26",
  "url": "https://osv.dev/vulnerability/CVE-2026-2439",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids",
    "summary": "Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids. The generate_session_id function in Concierge::Sessions::Base defaults to using the uuidgen command to generate a UUID, with a fallback to using Perl's built-in rand function. Neither of these methods are secure, and attackers are able to guess session_ids that can grant them access to systems. Specifically, * There is no warning when uuidgen fails. The software can be quietly using the fallback rand() function with no warnings if the command fails for any reason. * The uuidgen command will generate a time-based UUID if the system does not have a high-quality random number source, because the call does not explicitly specify the --random option. Note that the system time is shared in HTTP responses. * UUIDs are identifiers whose mere possession grants access, as per RFC 9562. * The output of the built-in rand() function is predictable and unsuitable for security applications.",
    "evidence": "osv:CVE-2026-2439",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-2439",
      "aliases": [
        "CVE-2026-2439"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/bwva/concierge-sessions",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "20bb28e92e8fba307c4ff8264701c215be65e73b"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "20bb28e92e8fba307c4ff8264701c215be65e73b"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-2439.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:25.200176903Z",
      "provider": "osv",
      "references": [
        "https://cpan.org/modules",
        "https://metacpan.org/release/BVA/Concierge-Sessions-v0.8.4/diff/BVA/Concierge-Sessions-v0.8.5#lib/Concierge/Sessions/Base.pm",
        "https://perldoc.perl.org/5.42.0/functions/rand",
        "https://security.metacpan.org/docs/guides/random-data-for-security.html",
        "https://www.rfc-editor.org/rfc/rfc9562.html#name-security-considerations",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/2xxx/CVE-2026-2439.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-2439",
        "https://github.com/bwva/Concierge-Sessions/commit/20bb28e92e8fba307c4ff8264701c215be65e73b",
        "https://github.com/bwva/Concierge-Sessions"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-338",
          "CWE-340"
        ],
        "cna_assigner": "CPANSec",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "0.8.1"
                  },
                  {
                    "fixed": "0.8.5"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "0.8.1"
                  },
                  {
                    "fixed": "0.8.5"
                  }
                ],
                "source": "DESCRIPTION"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/2xxx/CVE-2026-2439.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-2439",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 491945,
  "published_at": "2026-02-16T21:25:21.091+00:00"
}