ubuntu-cve-2026-53503
Vulnerability from osv_ubuntu
Published
2026-07-31 19:17
Modified
2026-08-06 00:20
Summary
Details

Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, Thumbor's filters:convolution(, , ) filter passes the user-controlled value to a C extension (thumbor/ext/filters/_convolution.c) where it is used as a divisor (for % and /) without validating columns > 0. When columns=0, the C code triggers undefined behavior; on x86_64 this reliably results in a fatal divide-by-zero trap (SIGFPE) and crashes the Thumbor process, causing a remote denial of service. This issue is fixed in 7.8.0.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "thumbor",
            "binary_version": "7.7.7-5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "thumbor",
        "purl": "pkg:deb/ubuntu/thumbor@7.7.7-5?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.7.7-4",
        "7.7.7-5"
      ]
    }
  ],
  "aliases": [],
  "details": "Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, Thumbor\u0027s filters:convolution(\u003cmatrix\u003e, \u003ccolumns\u003e, \u003cshould_normalize\u003e) filter passes the user-controlled \u003ccolumns\u003e value to a C extension (thumbor/ext/filters/_convolution.c) where it is used as a divisor (for % and /) without validating columns \u003e 0. When columns=0, the C code triggers undefined behavior; on x86_64 this reliably results in a fatal divide-by-zero trap (SIGFPE) and crashes the Thumbor process, causing a remote denial of service. This issue is fixed in 7.8.0.",
  "id": "UBUNTU-CVE-2026-53503",
  "modified": "2026-08-06T00:20:53Z",
  "published": "2026-07-31T19:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-53503"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-53503"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/thumbor/thumbor/security/advisories/GHSA-cqjp-jf4r-h5q9"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/thumbor/thumbor/commit/447e192e3fb92e64c12e5354a56a4a7133f69d73"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/thumbor/thumbor/releases/tag/7.8.0"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-53503"
  ]
}



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