Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Umbraco.Forms versions 16.0.0 to before 16.4.1 and 17.0.0 to before 17.1.1 are affected on Linux and Mac. An authenticated backoffice user can enumerate, traverse and read files on the server filesystem. Upgrade to 16.4.1 or 17.1.1; until then, restrict backoffice network access to trusted IP ranges.
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 |
|---|---|---|---|---|
| 6.0 | Medium | 4.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0046, the 39th percentile, on 10 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 15:22 UTC First seen by agentprime
- 31 Oct 2026, 15:22 UTC Confirmed by OSV