CVE-2026-76910
Unleash: Clone-feature lets a user copy a feature from a project they cannot read
Unleash is an open-source feature management platform. Prior to 8.0.3, cloneFeatureToggle and POST /api/admin/projects/:projectId/features/:featureName/clone authorize creation in the destination project but do not verify access to the source project. Because feature names are globally unique, a user with create or clone permission in one project who knows or guesses another project's feature name can copy that feature into the authorized project and inspect its strategy parameters, constraints, variants, and variant payloads. This issue is fixed in version 8.0.3.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
5.3
Unleash: Clone-feature lets a user copy a feature from a project they cannot read
Unleash is an open-source feature management platform. Prior to 8.0.3, cloneFeatureToggle and POST /api/admin/projects/:projectId/features/:featureName/clone authorize creation in the destination project but do not verify access to the source project. Because feature names are globally unique, a user with create or clone permission in one project who knows or guesses another project's feature name can copy that feature into the authorized project and inspect its strategy parameters, constraints, variants, and variant payloads. This issue is fixed in version 8.0.3.
- Record
CVE-2026-76910- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-639
- Updated
- 2026-11-02
EUVDEUVD-2026-84863
5.3
Unleash is an open-source feature management platform. Prior to 8.0.3, cloneFeatureToggle and POST /api/admin/projects/:projectId/features/:featureName/clone authorize creation in the destination project but do not verify access to the source project. Because feature names are globally unique, a user with create or clone permission in one project who knows or guesses another project's feature name can copy that feature into the authorized project and inspect its strategy parameters, constraints, variants, and variant payloads. This issue is fixed in version 8.0.3.
- Record
EUVD-2026-84863- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-8xcj-9hfr-fh9j
5.3
Unleash: Clone-feature lets a user copy a feature from a project they cannot read
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:
P1with a private or restricted feature namedsecret-feature, andP2where 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
P2and inspectsecret-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.
- Record
GHSA-8xcj-9hfr-fh9j- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-639
- Updated
- 2026-11-02
NVD
5.3
Unleash is an open-source feature management platform. Prior to 8.0.3, cloneFeatureToggle and POST /api/admin/projects/:projectId/features/:featureName/clone authorize creation in the destination project but do not verify access to the source project. Because feature names are globally unique, a user with create or clone permission in one project who knows or guesses another project's feature name can copy that feature into the authorized project and inspect its strategy parameters, constraints, variants, and variant payloads. This issue is fixed in version 8.0.3.
- Record
CVE-2026-76910- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/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 - Weakness
- CWE-639
- Updated
- 2026-11-02
OSV
5.3
Unleash: Clone-feature lets a user copy a feature from a project they cannot read
Unleash is an open-source feature management platform. Prior to 8.0.3, cloneFeatureToggle and POST /api/admin/projects/:projectId/features/:featureName/clone authorize creation in the destination project but do not verify access to the source project. Because feature names are globally unique, a user with create or clone permission in one project who knows or guesses another project's feature name can copy that feature into the authorized project and inspect its strategy parameters, constraints, variants, and variant payloads. This issue is fixed in version 8.0.3.
- Record
CVE-2026-76910- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-639
- Updated
- 2026-11-02
OSVGHSA-8xcj-9hfr-fh9j
5.3
Unleash: Clone-feature lets a user copy a feature from a project they cannot read
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:
P1with a private or restricted feature namedsecret-feature, andP2where 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
P2and inspectsecret-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.
- Record
GHSA-8xcj-9hfr-fh9j- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-639
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
unleash-servernpm |
before 8.0.3 | 8.0.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-76910 is a medium vulnerability (CVSS 5.3) in Unleash, published September 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.41%, the 35th percentile. Fixed in unleash-server 8.0.3.
References
github.com/Unleash/unleash/security/advisories/GHSA-8xcj-9hfr-fh9j
github.com/Unleash/unleash/commit/2dc6ac0e8ba524ec7a2e9bc96a0e01d9d6f5a35a
github.com/Unleash/unleash/releases/tag/v8.0.3
github.com/advisories/GHSA-8xcj-9hfr-fh9j
github.com/CVEProject/cvelistV5/tree/main/cves/2026/76xxx/CVE-2026-76910.json
nvd.nist.gov/vuln/detail/CVE-2026-76910
github.com/Unleash/unleash