Heap buffer overflow in gawk

{
  "id": "357b76036974dc354eefe87ca7f5db1c73d492e9a4c1d97053ca43fd39f33e31",
  "url": "https://osv.dev/vulnerability/CVE-2026-40469",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Heap buffer overflow in gawk",
    "summary": "Integer overflow vulnerability has been found in \"builtin.c\" program file of gawk (do_sub() routine). This issue could be used to overwrite gawk heap metadata and objects causing the program to crash. It affects 32-bit builds of gawk in versions 5.4.0 and below.",
    "evidence": "osv:CVE-2026-40469",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-40469",
      "aliases": [
        "CVE-2026-40469"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://cgit.git.savannah.gnu.org/cgit/gawk.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "ae1b2d508f46913269a9e62aceda3636afe8147b"
                }
              ],
              "database_specific": {
                "extracted_events": [
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                    "range": [
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                        "fixed": "ae1b2d508f46913269a9e62aceda3636afe8147b"
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                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-40469.json"
          }
        }
      ],
      "modified": "2026-10-31T10:30:31.699751413Z",
      "provider": "osv",
      "references": [
        "https://cgit.git.savannah.gnu.org/cgit/gawk.git/",
        "https://cert.pl/en/posts/2026/07/CVE-2026-40467",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40469.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-40469",
        "https://cgit.git.savannah.gnu.org/cgit/gawk.git/commit/?id=ae1b2d508f46913269a9e62aceda3636afe8147b"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-190"
        ],
        "cna_assigner": "CERT-PL",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "last_affected": "5.4.0"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "last_affected": "5.4.0"
                  }
                ],
                "source": "DESCRIPTION"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40469.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-40469",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 446631,
  "published_at": "2026-07-13T12:07:55.692+00:00"
}