{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:saitoha:libsixel:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0.11.0"
              },
              {
                "fixed": "1.8.7-r2"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE"
            ]
          },
          "events": [
            {
              "introduced": "361c78aeb8ea54ac25eb50aa22c976b5f48abffa"
            },
            {
              "fixed": "764f4e618c8bbc427fb74622e3227243fe6762fb"
            }
          ],
          "repo": "https://github.com/saitoha/libsixel",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-9jm7-77gr-qghv"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-190",
      "CWE-787"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44637.json"
  },
  "details": "libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a signed integer overflow in the SIXEL parser's image-buffer doubling loop can lead to an out-of-bounds heap write in sixel_decode_raw_impl. context-\u003epos_x grows by repeat_count on every sixel character with no upper bound check. Once pos_x approaches INT_MAX, the expression \"pos_x + repeat_count\" used to size the image buffer overflows signed int. Depending on how the overflow wraps, the resize check that should reject oversized buffers can be bypassed, after which a subsequent write computes a large attacker-influenced offset into image-\u003edata and writes past the allocation. Reachable from any caller that decodes attacker-supplied SIXEL data, including img2sixel. This vulnerability is fixed in 1.8.7-r2.",
  "id": "CVE-2026-44637",
  "modified": "2026-07-08T05:37:13.260925347Z",
  "published": "2026-05-14T20:02:32.034Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44637.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/saitoha/libsixel/security/advisories/GHSA-9jm7-77gr-qghv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44637"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "libsixel: integer overflow in parser"
}