How severe is CVE-2025-5689?

CVE-2025-5689 has a CVSS score of 8.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2025-5689?

CVE-2025-5689 affects the following packages: github.com/ubuntu/authd (Go). Ecosystems affected: Go.

How do I fix CVE-2025-5689?

Update github.com/ubuntu/authd to 0.5.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-5689 is resolved across your whole dependency graph.

How do I detect CVE-2025-5689 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ubuntu/authd, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-5689 if there is no patch (or I can't update yet)?

Close the privilege gap rather than the entry point: audit which accounts, roles and service identities can reach the affected operation, drop the component to the least privilege it actually needs, and review file and directory permissions created by earlier installs — a default left in place is what makes this reachable.

Is CVE-2025-5689 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-5689 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-5689?

CVE-2025-5689 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 23th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-5689?

CVE-2025-5689 is classified as Improper Privilege Management (CWE-269). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-5689 published, and has it been updated?

CVE-2025-5689 was published on June 16, 2025 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

HIGH severity

CVE-2025-5689 — authd

HIGHFix: ubuntu/authd@619ce8e

CVE-2025-5689 is a high-severity (CVSS 8.5) Improper Privilege Management vulnerability in github.com/ubuntu/authd. A fix is available for github.com/ubuntu/authd — see the affected versions and patch details below.

Improper Permission Management in SSH Session Handling

Also known asGHSA-g8qw-mgjx-rwjrGO-2025-3762

Published

Jun 16, 2025

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 31, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-5689.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs23th percentile — riskier than 23% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐹github.com/ubuntu/authd

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Impact

When an authd user logs in via SSH for the first time (meaning they do not yet exist in the authd user database) and successfully authenticates via the configured broker, the user is considered a member of the root group in the context of that SSH session. This situation may allow the user to read and write files that are accessible by the root group, to which they should not have access. The user does not get root privileges or any capabilities beyond the access granted to the root group.

Preconditions under which this vulnerability affects a system

authd was installed via the PPA.
An OAuth 2.0 application was registered in Microsoft Entra ID or Google IAM, and the respective authd broker was installed (authd-msentraid or authd-google) and configured.
sshd was configured to enable SSH access with authd, i.e.:
```
UsePAM yes
KbdInteractiveAuthentication yes
```
The username is allowed by the ssh_allowed_suffixes option in the broker configuriation.
The user is allowed by the allowed_users option in the broker configuration.
The user successfully authenticates via the authd broker (Entra ID or Google IAM).
The user did not log in locally before.

Patches

Fixed by https://github.com/ubuntu/authd/commit/619ce8e55953b970f1765ddaad565081538151ab

Workarounds

Configure the SSH server to not allow authenticating via authd, for example by setting UsePAM no or KbdInteractiveAuthentication no in the sshd_config (see https://documentation.ubuntu.com/authd/stable/howto/login-ssh/#ssh-configuration).

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/ubuntu/authd`	all versions	0.5.4`go get github.com/ubuntu/authd@v0.5.4`

Affected Products

1 product · 1 configurations

Application

authdcanonical

< 0.5.4

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ubuntu/authd, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/ubuntu/authd to 0.5.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-5689 is resolved across your whole dependency graph.
Workarounds
Close the privilege gap rather than the entry point: audit which accounts, roles and service identities can reach the affected operation, drop the component to the least privilege it actually needs, and review file and directory permissions created by earlier installs — a default left in place is what makes this reachable.

Frequently Asked Questions

### Impact When an authd user logs in via SSH for the first time (meaning they do not yet exist in the authd user database) and successfully authenticates via the configured broker, the user is considered a member of the root group in the context of that SSH session. This situation may allow the user to read and write files that are accessible by the root group, to which they should not have access. The user does not get root privileges or any capabilities beyond the access granted to the root group. **Preconditions under which this vulnerability affects a system** * authd was [installed via