CVE-2026-41487

MEDIUMCVSS 5.3/10EPSS 0.18%

Last modified

CVE-2026-41487 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Langfuse is an open source large language model engineering platform. From version 3.68.0 to before version 3.167.0, there is a role-based-access control flaw in the LLM connection update flow. EPSS estimates a 0.18% chance of exploitation in the next 30 days.

Description

Langfuse is an open source large language model engineering platform. From version 3.68.0 to before version 3.167.0, there is a role-based-access control flaw in the LLM connection update flow. An authenticated, low-privileged user of role “member” in a project could request the update of an existing LLM connection to an attacker-controlled baseUrl, causing Langfuse to reuse the stored provider secret and redirect the test request to an attacker-controlled endpoint. This could expose the plaintext provider LLM API key for that connection. The attack is only possible if a user is already part of a project and has “member” scoped access. This issue has been patched in version 3.167.0.

Metrics

CVSS 3.1
5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

CVSS 4.0
5.3/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.18%

7.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LangfuseLangfuse>= 3.68.0, < 3.167.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-41487?
Langfuse is an open source large language model engineering platform. From version 3.68.0 to before version 3.167.0, there is a role-based-access control flaw in the LLM connection update flow. An authenticated, low-privileged user of role “member” in a project could request the update of an existing LLM connection to an attacker-controlled baseUrl, causing Langfuse to reuse the stored provider secret and redirect the test request to an attacker-controlled endpoint. This could expose the plaintext provider LLM API key for that connection. The attack is only possible if a user is already part of a project and has “member” scoped access. This issue has been patched in version 3.167.0.
How severe is CVE-2026-41487?
CVE-2026-41487 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.
How do I fix CVE-2026-41487?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-41487?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST