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Fencer Intel
medium 5.3

CVE-2026-76910 json

Unleash: Clone-feature lets a user copy a feature from a project they cannot read

published last mo. modified last mo. also GHSA-8xcj-9hfr-fh9j , EUVD-2026-84863

cvss
5.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits
0
none known

Summary

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.

Patch / fix

  • npm unleash-server 8.0.3

Is CVE-2026-76910 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/Unleash/unleash/security/advisories/GHSA-8xcj-9hfr-fh9j referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.3 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
CNA 4.0 5.3 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

Affected packages

ecosystem package affected fixed in
npm unleash-server
<8.0.3
8.0.3

Affected products

  • Unleash unleash

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.