How severe is GHSA-8xcj-9hfr-fh9j?

No CVSS score has been assigned to GHSA-8xcj-9hfr-fh9j yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-8xcj-9hfr-fh9j?

GHSA-8xcj-9hfr-fh9j affects the following packages: unleash-server (npm). Ecosystems affected: npm.

How do I fix GHSA-8xcj-9hfr-fh9j?

Update unleash-server to 8.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8xcj-9hfr-fh9j is resolved across your whole dependency graph.

How do I detect GHSA-8xcj-9hfr-fh9j in my npm dependencies?

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

How do I mitigate GHSA-8xcj-9hfr-fh9j if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-8xcj-9hfr-fh9j actively exploited in the wild?

No public exploit code has been indexed for GHSA-8xcj-9hfr-fh9j 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 GHSA-8xcj-9hfr-fh9j?

GHSA-8xcj-9hfr-fh9j has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 22th 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 GHSA-8xcj-9hfr-fh9j?

GHSA-8xcj-9hfr-fh9j is classified as CWE-639 (CWE-639). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-8xcj-9hfr-fh9j published, and has it been updated?

GHSA-8xcj-9hfr-fh9j was published on September 22, 2026 and was last updated on September 22, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

Unleash: Clone-feature lets a user copy a feature from a project they cannot readGHSA-8xcj-9hfr-fh9j

Fix: Unleash/unleash@2dc6ac0

GHSA-8xcj-9hfr-fh9j is a CWE-639 vulnerability in unleash-server. A fix is available for unleash-server — see the affected versions and patch details below.

Also known asCVE-2026-76910

Published

Sep 22, 2026

Updated

Sep 22, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for GHSA-8xcj-9hfr-fh9j.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs22th percentile — riskier than 22% of all scored CVEsHighest risk

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

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

2other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

unleash-servernpm

15Kdownloads / week

Description

Summary

The clone-feature endpoint supports copying features across projects, but it does not verify that the caller can access the source project. A user with create permissions in one project can clone a feature from another project they cannot read and then inspect the copied configuration.

This vulnerability cannot be confirmed without Enterprise access. Report is based on a circumstantial evidence in the open-source repository.

Details

src/lib/features/feature-toggle/feature-toggle-service.ts implements cloneFeatureToggle. This operation needs authorization for both sides: permission to read/copy the source feature and permission to create the destination feature.

The clone path validates permissions against the destination project, but not against the source project that owns featureName. Because feature names are globally unique, a caller can reference a feature outside projects they can access.

PoC

Create or identify two projects: P1 with a private or restricted feature named secret-feature, and P2 where the attacker has clone/create permissions.
Authenticate as the attacker.
Send:

POST /api/admin/projects/P2/features/secret-feature/clone
Content-Type: application/json

{ "name": "secret-feature-copy" }

Open P2 and inspect secret-feature-copy. Verify if strategy parameters, constraints, variants, and variant payloads from the source feature have been copied.

Impact

Users with permissions on one project can disclose feature configuration from another project if they know or guess the source feature name. Feature names could be available in more public applications that have a common SDK access to multiple projects.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`unleash-server`	all versions	8.0.3`npm install unleash-server@8.0.3`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for unleash-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update unleash-server to 8.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8xcj-9hfr-fh9j is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Summary The clone-feature endpoint supports copying features across projects, but it does not verify that the caller can access the source project. A user with _create_ permissions in one project can clone a feature from another project they cannot read and then inspect the copied configuration. This vulnerability cannot be confirmed without Enterprise access. Report is based on a circumstantial evidence in the open-source repository. ### Details `src/lib/features/feature-toggle/feature-toggle-service.ts` implements `cloneFeatureToggle`. This operation needs authorization for both sides

O3 Security · Impact-Aware SCA

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