CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-53503
High (7.5). EPSS 0.8% chance of exploitation in the next 30 days. Fixed in thumbor 7.8.0.
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 x86_64 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.
Severity
- EPSS
- 0.8% chance of exploitation in the next 30 days; higher than 54% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-20, CWE-369
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-cqjp-jf4r-h5q9 | PyPI | thumbor | <7.8.0 | 7.8.0 |
| PYSEC-2026-3619 | PyPI | thumbor | <7.8.0 | 7.8.0 |