Firebird has a buffer overflow when parsing corrupted slice packets

{
  "id": "68bc8a7e7caf6ceeeeb89fe38abd7e94a4a6b820bbb524195731beeb870c117b",
  "url": "https://osv.dev/vulnerability/CVE-2026-33337",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Firebird has a buffer overflow when parsing corrupted slice packets",
    "summary": "Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, when deserializing a slice packet, the xdr_datum() function does not validate that a cstring length conforms to the slice descriptor bounds, allowing a cstring longer than the allocated buffer to overflow it. An unauthenticated attacker can exploit this by sending a crafted packet to the server, potentially causing a crash or other security impact. This issue has been fixed in versions 5.0.4, 4.0.7 and 3.0.14.",
    "evidence": "osv:CVE-2026-33337",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-33337",
      "aliases": [
        "CVE-2026-33337",
        "GHSA-89mq-229g-x47p"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/firebirdsql/firebird",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1767a517f9c99ec97160cacb452fdcfd83dca9be"
                },
                {
                  "fixed": "463bae029a4426deff7e9bb08a8317aaa398c7c7"
                },
                {
                  "introduced": "141bb5491d24cb363f03c5a0786a32f73a1faa5b"
                },
                {
                  "fixed": "26f6881c9eac77c5e3166d209682c0ebe8dd07c0"
                },
                {
                  "introduced": "af1546f15fa871b313ebcc7df1fd2df3c396c616"
                },
                {
                  "fixed": "f6d83a28c009ab039ea40ffdb4ccc58f190dfbe6"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.0.0"
                      },
                      {
                        "fixed": "3.0.14"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.0.0"
                      },
                      {
                        "fixed": "4.0.7"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.0.0"
                      },
                      {
                        "fixed": "5.0.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "463bae029a4426deff7e9bb08a8317aaa398c7c7"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.0.14"
                  },
                  {
                    "range": [
                      {
                        "fixed": "26f6881c9eac77c5e3166d209682c0ebe8dd07c0"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v4.0.7"
                  },
                  {
                    "range": [
                      {
                        "fixed": "f6d83a28c009ab039ea40ffdb4ccc58f190dfbe6"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v5.0.4"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v3.0.13",
            "v4.0.6",
            "v5.0.3",
            "v5.0.2",
            "v3.0.12",
            "v4.0.5",
            "v5.0.1",
            "v5.0.0",
            "v4.0.4",
            "v3.0.11",
            "v4.0.3",
            "v4.0.2",
            "v3.0.10",
            "v3.0.9",
            "v4.0.1",
            "v3.0.8",
            "v4.0.0",
            "R3_0_7",
            "R3_0_6",
            "R3_0_5",
            "R3_0_4",
            "R3_0_3",
            "R3_0_2",
            "R3_0_1",
            "R3_0_0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33337.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:48.105774603Z",
      "provider": "osv",
      "references": [
        "https://github.com/FirebirdSQL/firebird/releases/tag/v3.0.14",
        "https://github.com/FirebirdSQL/firebird/releases/tag/v4.0.7",
        "https://github.com/FirebirdSQL/firebird/releases/tag/v5.0.4",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33337.json",
        "https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-89mq-229g-x47p",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-33337"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-120",
          "CWE-502"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33337.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-33337",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 515936,
  "published_at": "2026-04-17T18:48:47.953+00:00"
}