CVE-2026-53503

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/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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/thumbor/thumbor/commit/447e192e3fb92e64c12e5354a56a4a7133f69d73
https://github.com/thumbor/thumbor/releases/tag/7.8.0
https://github.com/thumbor/thumbor/security/advisories/GHSA-cqjp-jf4r-h5q9
https://github.com/thumbor/thumbor/security/advisories/GHSA-cqjp-jf4r-h5q9

Configurations

No configuration.

History

No history.

Information

Published : 2026-07-31 19:17

Updated : 2026-09-08 20:51

NVD link : CVE-2026-53503

Mitre link : CVE-2026-53503

CVE.ORG link : CVE-2026-53503

JSON object : View

Products Affected

No product.

CWE

CWE-20

Improper Input Validation

CWE-369

Divide By Zero

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