CVE-2026-53505: Thumbor

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, Thumbor's filters:proportion(<value>) filter does not enforce an upper bound on <value> and runs in the post-transform phase. An attacker can trigger extremely large resizes (CPU/memory exhaustion) and cause denial of service. This issue is fixed in 7.8.0.

Affected products

• Thumbor Thumbor: before 7.8.0 (fixed in 7.8.0)

Published 2026-07-31. Last modified 2026-09-08.