What’s Vulnerable › Vulnerabilities

CVE-2026-53500: Thumbor treats ALLOWED_SOURCES string patterns as unescaped regex, allowing hostname bypass via wildcard dot

• Severity: high (CVSS 8.2 v3.1)
• 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-918

Description

Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, the ALLOWED_SOURCES configuration passes plain strings to re.match() without escaping dots, so a hostname differing at dot positions can match the allowlist. This issue is fixed in 7.8.0.

Affected products

• thumbor: before 7.8.0

References

• https://github.com/thumbor/thumbor/commit/68876715350c6c8f49c324e5515e64908830aed7
• https://github.com/thumbor/thumbor/releases/tag/7.8.0
• https://github.com/thumbor/thumbor/security/advisories/GHSA-6x26-6r6f-m537
• https://github.com/thumbor/thumbor/security/advisories/GHSA-6x26-6r6f-m537

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