UBUNTU-CVE-2026-53501

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Source
https://ubuntu.com/security/CVE-2026-53501
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-53501.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-53501
Upstream
Published
2026-07-31T19:17:00Z
Modified
2026-08-06T00:20:53Z
Severity
  • 8.2 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:26.04:LTS / thumbor

Package

Name
thumbor
Purl
pkg:deb/ubuntu/thumbor?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

7.*
7.7.7-4
7.7.7-5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "thumbor",
            "binary_version": "7.7.7-5"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-53501.json"