What’s Vulnerable › Vulnerabilities

CVE-2026-53502: Thumbor has path traversal via post-validation URL decoding bypass in file_loader

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-31 · updated 2026-09-08
• Weakness: CWE-22

Description

Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, file_loader decodes percent-encoded path segments after its root-boundary validation, allowing traversal outside FILE_LOADER_ROOT_PATH through watermark or frame filter input. This issue is fixed in 7.8.0.

Affected products

• thumbor: before 7.8.0

References

• https://github.com/thumbor/thumbor/commit/3b986d13677b30fe6651c8c72ebb25957ac0a40d
• https://github.com/thumbor/thumbor/releases/tag/7.8.0
• https://github.com/thumbor/thumbor/security/advisories/GHSA-cj54-hpcc-gj6h
• https://github.com/thumbor/thumbor/security/advisories/GHSA-cj54-hpcc-gj6h

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