CVE-2026-63398 Coop - Broken Access Control

Coop prior to 1.0.2 contains a broken access control vulnerability caused by SAML strategy's verify callback resolving users by email without organization binding, letting attackers with control of a SAML IdP signing key perform cross-tenant account takeover, exploit requires matching signing certificate in target organization.

CVSS base score 7.4 /10
High
CISA KEV
Not listed
Public exploit
None known
EPSS
0.18% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Broken Access Control
Impact
Broken Access Control
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/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
Published
30 October 2026
Updated
1 November 2026
Weakness
CWE-287

Vendor fix

Update to version 1.0.2 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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