CVE-2026-53505

Thumbor proportion filter allows unbounded post-transform resize leading to remote DoS

HIGH
7.5
CVSS Score
Published: July 31, 2026 at 07:00 PM UTC
Updated: September 8, 2026 at 09:09 PM UTC
1 product affected across 1 vendorThumbor

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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
PoC

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 7.8.0
Affected range stops below 7.8.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-400

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