FLTK through 1.4.5 Stack Buffer Overflow via Fl_BMP_Image colors_used Field

{
  "id": "23cc4cc58789047d7df69de9534ffe79bdd4b5f5c1e987f786ed324f29d688b2",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-116723",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "FLTK through 1.4.5 Stack Buffer Overflow via Fl_BMP_Image colors_used Field",
    "summary": "FLTK through 1.4.5 contains a stack-based buffer overflow vulnerability in Fl_BMP_Image::load_bmp_() that allows attackers to corrupt stack memory by supplying an oversized BMP colors_used field. Attackers can craft BMP or ICO files with colors_used above 256 to overflow the 768-byte colormap array, causing crashes or potential code execution.",
    "evidence": "cve:CVE-2026-116723",
    "products": [
      {
        "name": {
          "value": "fltk",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-116723",
      "aliases": [
        "CVE-2026-116723"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "version": "4.0",
            "baseScore": 8.5,
            "attackVector": "LOCAL",
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "userInteraction": "PASSIVE",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH"
          }
        },
        {
          "format": "CVSS",
          "cvssV3_1": {
            "scope": "UNCHANGED",
            "version": "3.1",
            "baseScore": 7.8,
            "attackVector": "LOCAL",
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "integrityImpact": "HIGH",
            "userInteraction": "REQUIRED",
            "attackComplexity": "LOW",
            "availabilityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "confidentialityImpact": "HIGH"
          }
        }
      ],
      "affected": [
        {
          "repo": "https://github.com/fltk/fltk",
          "vendor": "fltk",
          "product": "fltk",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "custom",
              "lessThanOrEqual": "1.4.5"
            }
          ],
          "packageURL": "pkg:github/fltk/fltk",
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-26T21:52:27.469Z",
      "provider": "cve",
      "references": [
        "https://github.com/fltk/fltk/issues/1632",
        "https://github.com/fltk/fltk",
        "https://github.com/fltk/fltk/commit/3a049d8262dc759cf9737339420e8457e24c0cb1",
        "https://github.com/fltk/fltk/blob/release-1.4.5/src/Fl_BMP_Image.cxx#L255-L265",
        "https://hackmd.io/@haindpwn/fltk-bmp-image-stack-heap-overflow",
        "https://www.vulncheck.com/advisories/fltk-through-1.4.5-stack-buffer-overflow-via-fl-bmp-image-colors-used-field"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
          "shortName": "VulnCheck",
          "dateUpdated": "2026-10-26T21:52:27.469Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-116723",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 353926,
  "published_at": "2026-10-26T21:52:27.469+00:00"
}