CVE-2026-53500Public exploitNetwork attack vector

SSRF via unescaped source-host patterns

Published Jul 31, 2026 · Updated Jul 31, 2026

SSRF in thumbor before 7.8.0 allows remote attackers to fetch images from arbitrary hosts through crafted source URLs. In thumbor/loaders/http_loader.py, validate() anchors plain ALLOWED_SOURCES strings but sends them to re.match without escaping dots, so hostname dots act as regex wildcards. Exploitation requires a plain-string allowlist entry and attacker control of the image URL, exposing otherwise blocked hosts and returned image data.

CVSS severity8.2
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in thumbor before 7.8.0 allows remote attackers to fetch images from arbitrary hosts through crafted source URLs. In thumbor/loaders/http_loader.py, validate() anchors plain ALLOWED_SOURCES strings but sends them to re.match without escaping dots, so hostname dots act as regex wildcards. Exploitation requires a plain-string allowlist entry and attacker control of the image URL, exposing otherwise blocked hosts and returned image data.

The record

CVE
CVE-2026-53500
Published
Jul 31, 2026
Updated
Jul 31, 2026
Vendor
thumbor
Product
thumbor
Classifications
CWE-918, T1190
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

8.2GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L

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-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

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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