{"id":"CVE-2026-53503","summary":"Thumbor convolution filter allows divide-by-zero in C extension leading to remote DoS","details":"Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, Thumbor's 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.","aliases":["GHSA-cqjp-jf4r-h5q9"],"modified":"2026-08-02T09:08:28.610622Z","published":"2026-07-31T18:54:20.747Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-20","CWE-369"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53503.json"},"references":[{"type":"WEB","url":"https://github.com/thumbor/thumbor/releases/tag/7.8.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53503.json"},{"type":"ADVISORY","url":"https://github.com/thumbor/thumbor/security/advisories/GHSA-cqjp-jf4r-h5q9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53503"},{"type":"FIX","url":"https://github.com/thumbor/thumbor/commit/447e192e3fb92e64c12e5354a56a4a7133f69d73"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/thumbor/thumbor","events":[{"introduced":"0"},{"fixed":"447e192e3fb92e64c12e5354a56a4a7133f69d73"},{"fixed":"a366291cfcd29ec140911c97ee8e0e794f2a40f9"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"7.8.0"}]}}],"versions":["7.7.7","7.7.6","7.7.5","7.7.4","7.7.3","7.7.2","7.7.1","7.7.0","7.6.0","7.5.2","7.5.1","7.5.0","7.4.7","7.4.6","7.4.5","7.4.4","7.4.3","7.4.2","7.4.1","7.3.2","7.3.1","7.3.0","7.2.1","7.2.0","7.1.2","7.1.1","7.1.0","7.0.12","7.0.11","7.0.10","7.0.9","7.0.8","7.0.7","7.0.6","7.0.5","7.0.3","7.0.2","7.0.1","7.0.0","7.0.0b1","7.0.0a5","7.0.0a4","7.0.0a3","7.0.0a2","7.0.0a1","6.7.1","6.7.0","6.6.1","6.6.0","6.5.2","6.5.0","6.4.3","6.4.2","6.4.1","6.4.0","6.3.2","6.3.3rc","6.3.1","6.3.0","6.2.1","6.2.0","6.0.1","6.0.0","6.0.0b5","6.0.0b3","6.0.0b2","6.0.0b1","5.2.1","5.2.0","5.1.0","5.0.6","5.0.5","5.0.4","5.0.3","5.0.2","5.0.1","5.0.0","5.0.0rc2","5.0.0-rc1","4.12.2","4.12.1","4.12.0","4.11.1","4.11.0","4.10.3","4.10.2","4.10.1","4.10.0","4.9.1","4.9.0","4.8.7","4.8.6","4.8.3","4.8.2","4.8.1","4.8.0","4.7.1","4.7.0","4.6.0","4.5.4","4.5.3","4.5.2","4.5.1","4.5.0","4.4.1","4.4.0","4.3.0","4.2.1","4.2.0","4.1.3","4.1.2","4.1.1","4.1.0","4.0.4","4.0.3","4.0.0","3.15.0","3.14.7","3.14.6","3.14.5","3.14.4","3.14.3","3.14.2","3.14.1","3.14.0","3.13.3","3.13.2","3.13.1","3.13.0","3.12.2","3.12.1","3.12.0","3.11.1","3.11.0","3.10.2","3.10.1","3.10.0","3.9.4","3.9.3","3.9.2","3.9.1","3.9.0","3.8.1","3.8.0","3.7.3","3.7.2","3.7.1","3.7.0","3.6.11","3.6.10","3.6.9","3.6.8","3.6.7","3.6.6","3.6.5","3.6.4","3.6.3","3.6.2","3.6.1","3.6.0","3.5.2","3.5.1","3.5.0","3.4.2","3.4.1","3.4.0","3.2.0","3.3.0","3.1.1","3.1.0","3.0.2","2.8.1","3.0.1","3.0.0","2.8.0","2.7.8","2.7.6","2.7.5","2.7.4","2.7.3","2.7.2","2.7.1","2.7.0","2.6.6","2.6.5","2.6.4","2.6.3","2.6.2","2.6.1","2.6.0","2.5.2","2.5.1","2.5.0","2.4.9","2.4.8","2.4.7","2.4.6","2.4.5","2.4.4","2.4.3","2.4.2","2.4.1","2.3.0","2.0.5","2.0.4","2.0.2","0.9.7","0.9.6","0.9.4","0.9.5","0.9.3","0.9.1","0.9.0","0.8.4","0.8.3","0.8.2","0.8.0","0.7.14","0.7.13","0.7.12","0.7.11","0.7.10","0.7.9","0.7.0","0.6.5","0.6.4","0.6.3","0.6.2","0.6.1","0.5.1","0.5.0","0.4.1","0.4.0","0.3.1","0.3.0","0.2.1","0.2.0","0.1.1","0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53503.json","vanir_signatures_modified":"2026-08-02T09:08:28Z","vanir_signatures":[{"source":"https://github.com/thumbor/thumbor/commit/447e192e3fb92e64c12e5354a56a4a7133f69d73","target":{"file":"thumbor/ext/filters/_convolution.c"},"deprecated":false,"digest":{"line_hashes":["331860887079222848408616751728650524390","102845713418915347401106561625760000959","141057370814210221605386325158426071900","327776404604771883483459886814002358669"],"threshold":0.9},"id":"CVE-2026-53503-1d1ba0c2","signature_type":"Line","signature_version":"v1"},{"target":{"file":"thumbor/ext/filters/_convolution.c","function":"_convolution_apply"},"deprecated":false,"digest":{"function_hash":"71343731735558916145751808373970799556","length":1828},"id":"CVE-2026-53503-38b415f2","signature_type":"Function","signature_version":"v1","source":"https://github.com/thumbor/thumbor/commit/447e192e3fb92e64c12e5354a56a4a7133f69d73"}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}