Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Thumbor versions before 7.8.0 are affected. The proportion filter accepts an unbounded scaling value and applies it after the main transform, so an attacker who can send requests to the server can trigger very large resizes that exhaust CPU and memory and can cause a denial of service. If unsafe URLs are enabled, no authentication is needed; otherwise the attacker needs a valid signed URL. Upgrade to Thumbor 7.8.0 or later.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.5 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0061, the 49th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:40 UTC First seen by agentprime
- 31 Oct 2026, 14:40 UTC Confirmed by OSV