CVE-2026-53505 — Thumbor proportion filter allows unbounded post-transform resize leading to remote DoS
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 …
Published: 2026-07-31 · CVSS: 7.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7