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Fencer Intel
medium 6.9

CVE-2026-63399 json

Coop: Unauthenticated org provisioning via GraphQL Mutation.createOrg

published 4mo ago modified 5d ago also EUVD-2026-114547 , GHSA-jcph-g6qv-g475

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository roostorg/coop. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
6.9
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

Coop is an open source review and moderation tool from ROOST. Prior to 1.0.0, the `GraphQL` `Mutation.createOrg` operation allows an unauthenticated actor to create arbitrary organizations on a publicly accessible instance. In addition to creating noise in the logs, the lack of rate limiting could potentially lead to database exhaustion. Running the service on an authenticated private network prevents outside actors from directly querying the `GraphQL` API. This issue is fixed in version 1.0.0.

Patch / fix

Is CVE-2026-63399 in your stack? 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
yes
Technical impact
partial
Assessed
5d ago

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/roostorg/coop/security/advisories/GHSA-jcph-g6qv-g475 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/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 products

  • roostorg coop

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality
  • CWE-799 Improper Control of Interaction Frequency

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.

The maintainers of roostorg/coop published their own advisory on GitHub. Reviewed sources take precedence over it.