{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:tukaani:xz:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "5.8.3"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4b73f2ec19a99ef465282fbce633e8deb33691b3"
            },
            {
              "fixed": "c8c22869e780ff57c96b46939c3d79ff99395f87"
            }
          ],
          "repo": "https://github.com/tukaani-project/xz",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-x872-m794-cxhv"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-122"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34743.json"
  },
  "details": "XZ Utils provide a general-purpose data-compression library plus command-line tools. Prior to version 5.8.3, if lzma_index_decoder() was used to decode an Index that contained no Records, the resulting lzma_index was left in a state where where a subsequent lzma_index_append() would allocate too little memory, and a buffer overflow would occur. This issue has been patched in version 5.8.3.",
  "id": "CVE-2026-34743",
  "modified": "2026-07-27T03:56:14.712168802Z",
  "published": "2026-04-02T18:36:37.450Z",
  "references": [
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/03/31/13"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tukaani-project/xz/releases/tag/v5.8.3"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2026/07/msg00034.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34743.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/tukaani-project/xz/security/advisories/GHSA-x872-m794-cxhv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34743"
    },
    {
      "type": "FIX",
      "url": "https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U",
      "type": "CVSS_V4"
    }
  ],
  "summary": "XZ Utils: Buffer overflow in lzma_index_append()"
}