CVE-2026-53501

NameCVE-2026-53501
DescriptionThumbor 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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
thumbor (PTS)forky, sid7.8.0-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
thumborsource(unstable)7.8.0-1

Notes

https://github.com/thumbor/thumbor/security/advisories/GHSA-mw3h-qjxj-6xg9
Fixed by: https://github.com/thumbor/thumbor/commit/e3ae3e2500537b4d735df4144129a649374bb70b (7.8.0)

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