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Fencer Vulns
high 7.1

CVE-2026-77426 json

Unleash: Missing await on permission check + cross-project IDOR in admin API

published 2026-09-22 47 d ago modified 2026-09-23 46 d ago also GHSA-72h8-wp98-7hch , EUVD-2026-84867

cvss
7.1
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

Unleash is an open-source feature management platform. Prior to 8.0.3, the Unleash admin API contains five authorization vulnerabilities. POST /api/admin/segments/strategies assigns the Promise returned by hasPermission without awaiting it, allowing authenticated users to modify segment assignments without UPDATE_FEATURE_STRATEGY permission for the target project and environment. GET /api/admin/projects/:projectId/features/:featureName/environments/:environment/variants does not bind the requested feature to projectId, allowing cross-project variant configuration disclosure. GET .../strategies/:strategyId uses strategyId without validating the project and feature context, allowing cross-project strategy configuration disclosure. getEnvironmentInfo does not validate that the requested feature belongs to the supplied project, allowing cross-project environment information disclosure. PUT /:projectId/tags accepts feature identifiers without verifying that they belong to the URL project, allowing cross-project tag modification. This issue is fixed in version 8.0.3.

Patch / fix

  • npm unleash-server 8.0.3

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
46 d ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/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
  • CWE-862 Missing Authorization

References

Sources

Fencer Vulns 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.