CVE-2026-53505Public exploitNetwork attack vectorHinoki check available

Service interruption via unbounded post-transform resize

Published Jul 31, 2026 · Updated Jul 31, 2026

Resource exhaustion in thumbor before 7.8.0 allows remote attackers to interrupt the service through a crafted proportion filter. The proportion method in thumbor/filters/proportion.py accepts an unbounded decimal multiplier, computes oversized post-transform dimensions, and passes them to engine.resize after earlier request-size limits have run. The built-in filter is enabled by default; unauthenticated reachability requires unsafe URLs, while signed deployments require a valid signed URL, and processing exhausts CPU or memory and can terminate the process.

CVSS severity7.5
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Resource exhaustion in thumbor before 7.8.0 allows remote attackers to interrupt the service through a crafted proportion filter. The proportion method in thumbor/filters/proportion.py accepts an unbounded decimal multiplier, computes oversized post-transform dimensions, and passes them to engine.resize after earlier request-size limits have run. The built-in filter is enabled by default; unauthenticated reachability requires unsafe URLs, while signed deployments require a valid signed URL, and processing exhausts CPU or memory and can terminate the process.

The record

CVE
CVE-2026-53505
Published
Jul 31, 2026
Updated
Jul 31, 2026
Vendor
thumbor
Product
thumbor
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 31, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 7.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

thumbor · thumborversion=< 7.8.0

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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