FKIE_CVE-2026-73639

Vulnerability from fkie_nvd - Published: 2026-09-17 22:17 - Updated: 2026-09-22 19:16
Severity
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Summary
Imager::File::PNG versions from 1.003 before 1.004 for Perl write past the end of the row buffer reading a PNG with a tRNS transparency chunk in read_direct8. With a tRNS chunk, read_direct8() adds an alpha channel to the image it creates but still sizes the row buffer from the original channel count. libpng expands the transparency into that extra channel, so png_read_row() fills one channel more than the buffer holds, at one byte per sample, and writes width bytes past the end of the allocation. Palette images go to read_paletted() and 16-bit images to read_direct16(), which sizes its buffer from png_get_rowbytes() and allocates enough for the expanded row. The same reader ships bundled in the Imager distribution. Reading an attacker-supplied PNG through Imager->read() corrupts the heap, which can crash the process.
References
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://github.com/tonycoz/imager/commit/d973bd7e8843f084e8071caa24b89545c88b1e4b.patch
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://github.com/tonycoz/imager/pull/567
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://github.com/tonycoz/imager/security/advisories/GHSA-jhx5-34j8-9g88
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://metacpan.org/release/TONYC/Imager-1.035/changes
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://metacpan.org/release/TONYC/Imager-File-PNG-1.004/changes
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/09/17/6
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Imager::File::PNG"
          ],
          "packageName": "Imager-File-PNG",
          "packageURL": "pkg:cpan/Imager-File-PNG",
          "programFiles": [
            "impng.c"
          ],
          "programRoutines": [
            {
              "name": "read_direct8"
            }
          ],
          "repo": "https://github.com/tonycoz/imager",
          "versions": [
            {
              "lessThan": "1.004",
              "status": "affected",
              "version": "1.003",
              "versionType": "custom"
            }
          ]
        },
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Imager::File::PNG"
          ],
          "packageName": "Imager",
          "packageURL": "pkg:cpan/Imager",
          "programFiles": [
            "PNG/impng.c"
          ],
          "programRoutines": [
            {
              "name": "read_direct8"
            }
          ],
          "repo": "https://github.com/tonycoz/imager",
          "versions": [
            {
              "lessThan": "1.035",
              "status": "affected",
              "version": "1.034",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Imager::File::PNG versions from 1.003 before 1.004 for Perl write past the end of the row buffer reading a PNG with a tRNS transparency chunk in read_direct8.\n\nWith a tRNS chunk, read_direct8() adds an alpha channel to the image it creates but still sizes the row buffer from the original channel count. libpng expands the transparency into that extra channel, so png_read_row() fills one channel more than the buffer holds, at one byte per sample, and writes width bytes past the end of the allocation. Palette images go to read_paletted() and 16-bit images to read_direct16(), which sizes its buffer from png_get_rowbytes() and allocates enough for the expanded row.\n\nThe same reader ships bundled in the Imager distribution.\n\nReading an attacker-supplied PNG through Imager-\u003eread() corrupts the heap, which can crash the process."
    }
  ],
  "id": "CVE-2026-73639",
  "lastModified": "2026-09-22T19:16:44.383",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-73639",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-22T18:04:27.077498Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-17T22:17:03.763",
  "references": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://github.com/tonycoz/imager/commit/d973bd7e8843f084e8071caa24b89545c88b1e4b.patch"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://github.com/tonycoz/imager/pull/567"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://github.com/tonycoz/imager/security/advisories/GHSA-jhx5-34j8-9g88"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/TONYC/Imager-1.035/changes"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/TONYC/Imager-File-PNG-1.004/changes"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/17/6"
    }
  ],
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary"
    }
  ]
}



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