Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Thumbor versions before 7.8.0 treat plain-string entries in ALLOWED_SOURCES as unescaped regular expressions, so a dot in a hostname matches any character. An attacker who can influence the image URL, which is possible with the default ALLOW_UNSAFE_URL setting or when user input reaches a signed URL endpoint, can fetch images from hosts outside the allowlist. Upgrade to Thumbor 7.8.0 or later; to work around the issue before upgrading, supply compiled regular expression patterns for ALLOWED_SOURCES instead of plain strings.
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 |
|---|---|---|---|---|
| 8.2 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0050, the 43rd percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:41 UTC First seen by agentprime
- 31 Oct 2026, 14:41 UTC Confirmed by OSV