Auth bypass in Langfuse
CVE-2025-59305
Improper authorization in the background migration endpoints of Langfuse 3.1 before d67b317 allows any authenticated user to invoke migration control functions. This can lead to data corruption or denial of service through unauthorized access to TRPC endpoints such as backgroundMigrations.all, backgroundMigrations.status, and backgroundMigrations.retry.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (17.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 17.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- depthfirst.com/post/how-an-authorization-flaw-reveals-a-common-security-blind-s… (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2025-59305?
- CVE-2025-59305 is a high-severity vulnerability in Langfuse, classified under Improper Authorization. CVSS score: 7.6/10. Published 2025-09-24.
- How severe is CVE-2025-59305?
- High severity. CVSS v3 base score is 7.6 out of 10.
- Is CVE-2025-59305 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.