CVE-2026-41487: Langfuse is an open source large language model engineering platform

Routine

MEDIUM 5.4UPGRADE

CVE-2026-41487 is a medium-severity flaw (CVSS 5.4) affecting langfuse. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 92%)
CISA exploited list	No
Weakness	CWE-284
Published	2026-05-08
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: langfuse

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-08 15:16 UTCPublished CVE record published
2026-06-17 10:46 UTCUpdated Record last modified

langfuse langfuse UPGRADE

Affected: >= 3.68.0 and < 3.167.0

Fixed in: 3.167.0

Safe to downgrade to: a release before 3.68.0

1. Check installed version

apt-cache policy langfuse || rpm -q langfuse || langfuse --version

2. UPGRADE to 3.167.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade langfuse

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade langfuse

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.68.0 (Debian / Ubuntu)

apt-cache madison langfuse sudo apt install langfuse=<VERSION_BEFORE_3.68.0> sudo apt-mark hold langfuse

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list langfuse sudo dnf downgrade langfuse-<VERSION_BEFORE_3.68.0> sudo dnf versionlock add langfuse

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-41487?

langfuse: upgrade to 3.167.0. Exact commands for each OS are on this page.

Is CVE-2026-41487 being exploited?

CVE-2026-41487 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-41487 affect?

CVE-2026-41487 affects langfuse. Severity is medium (CVSS 5.4). 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

How urgent is CVE-2026-41487?

Priority 21/100. No elevated risk signals yet.

References

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