{"id":"CVE-2026-53503","title":"Thumbor is an open-source photo thumbnail service by globo.com","summary":"Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, Thumbor's filters:convolution(<matrix>, <columns>, <should_normalize>) filter passes the user-controlled <columns> value to a C extension (thumbor/ext/filter…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-20","CWE-369"],"vendor":"thumbor","product":"thumbor","affected":["thumbor <= 7.7.7"],"patched":["thumbor 7.8.0"],"published":"2026-07-31","updated":"2026-09-08","sourceUpdated":"2026-09-08T20:51:43.490","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53503","references":[{"url":"https://github.com/thumbor/thumbor/commit/447e192e3fb92e64c12e5354a56a4a7133f69d73","label":"security-advisories@github.com"},{"url":"https://github.com/thumbor/thumbor/releases/tag/7.8.0","label":"security-advisories@github.com"},{"url":"https://github.com/thumbor/thumbor/security/advisories/GHSA-cqjp-jf4r-h5q9","label":"security-advisories@github.com"},{"url":"https://github.com/thumbor/thumbor/security/advisories/GHSA-cqjp-jf4r-h5q9","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://github.com/advisories/GHSA-cqjp-jf4r-h5q9"}],"tags":["nvd","ghsa","pip"],"epss":0.00412,"epssPercentile":0.35101,"aliases":["GHSA-cqjp-jf4r-h5q9"],"ecosystem":"pip","ingestedAt":"2026-07-31T19:01:36.544Z","slug":"CVE-2026-53503","body":"## Overview\n\nThumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, Thumbor's filters:convolution(<matrix>, <columns>, <should_normalize>) filter passes the user-controlled <columns> 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-53503)\n\nAffected packages:\n\n- `thumbor <= 7.7.7`\n\nPatched in:\n\n- `thumbor 7.8.0`\n\nSource: https://github.com/advisories/GHSA-cqjp-jf4r-h5q9","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}