CVE-2026-53501High· 8.2▾ TwilightThumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, Thumbor’s HMAC validation can be bypassed due to the use of Python’s .replace() when removing the signature from the URL before validation. Since .replace() …
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 45.1 · likelihood 0.1 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Exploit-prediction probability, daily snapshots since Aug 1.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.2%
Last analysed / modified upstream
0.2% → 0.4%
Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, Thumbor’s HMAC validation can be bypassed due to the use of Python’s .replace() when removing the signature from the URL before validation. Since .replace() removes all occurrences of the substring, an attacker can insert the same signature multiple times in the URL and manipulate the final URL used for validation. This allows crafting URLs where the validated string differs from the actual requested resource, enabling loading images from unintended domains or paths. This issue is fixed in 7.8.0.
Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Affected packages:
thumbor <= 7.7.7Patched in:
thumbor 7.8.0Connected by shared product, vendor, weakness, or advisory.
CVE-2026-53505High· 7.5Thumbor is an open-source photo thumbnail service by globo.com
CVE-2026-53502HighThumbor is an open-source photo thumbnail service by globo.com
CVE-2026-53500High· 8.2Thumbor is an open-source photo thumbnail service by globo.com
CVE-2026-53503High· 7.5Thumbor is an open-source photo thumbnail service by globo.com
CVE-2026-53504High· 7.5Thumbor is an open-source photo thumbnail service by globo.com
CVE-2025-55311Medium· 6.5An issue was discovered in Foxit PDF and Editor for Windows and macOS before 13.2 and 2025 before 2025.2