UBUNTU-CVE-2026-53503

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Source
https://ubuntu.com/security/CVE-2026-53503
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-53503.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-53503
Upstream
Published
2026-07-31T19:17:00Z
Modified
2026-08-06T00:20:53Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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 filters:convolution(<matrix>, <columns>, <should_normalize>) filter passes the user-controlled <columns> value to a C extension (thumbor/ext/filters/convolution.c) where it is used as a divisor (for % and /) without validating columns > 0. When columns=0, the C code triggers undefined behavior; on x8664 this reliably results in a fatal divide-by-zero trap (SIGFPE) and crashes the Thumbor process, causing a remote denial of service. 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-2026-53503.json"