Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The Lemur package (PyPI) before 1.9.2 reads the signing algorithm from the unverified JWT header instead of pinning it on the server. With PyJWT 2.x, single-request forgery is blocked by the library, so exploitation requires a separate flaw that discloses the LEMUR_TOKEN_SECRET or a future move to asymmetric signing; the source gives few details on the exact impact. Upgrade to version 1.9.2 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 |
|---|---|---|---|---|
| 4.8 | Medium | 3.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0015, the 4th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 15:02 UTC First seen by agentprime
- 31 Oct 2026, 15:02 UTC Confirmed by OSV