CVE-2026-1529
📋 TL;DR
This vulnerability in Keycloak allows attackers to modify invitation token payloads to self-register into unauthorized organizations. Attackers can exploit missing cryptographic signature verification in JWT tokens to gain unauthorized access. Organizations using vulnerable Keycloak versions for identity and access management are affected.
💻 Affected Systems
- Keycloak
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of organizational boundaries, allowing attackers to access sensitive data and systems across multiple organizations within the Keycloak deployment.
Likely Case
Unauthorized access to a single organization's resources, potentially leading to data exposure or privilege escalation within that organization.
If Mitigated
Limited impact with proper network segmentation and additional authentication layers preventing lateral movement.
🎯 Exploit Status
Exploitation requires obtaining a legitimate invitation token first, but token modification is trivial once obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Red Hat advisory RHSA-2026:2364 for specific patched versions
Vendor Advisory: https://access.redhat.com/errata/RHSA-2026:2364
Restart Required: Yes
Instructions:
1. Review Red Hat advisory RHSA-2026:2364. 2. Update Keycloak to patched version. 3. Restart Keycloak service. 4. Verify fix implementation.
🔧 Temporary Workarounds
Disable organization invitations
allTemporarily disable organization invitation functionality until patched
Configure Keycloak to disable organization invitation features via admin console or configuration files
Implement additional token validation
allAdd custom token validation to verify organization ID and email consistency
Implement custom authenticator or token validator in Keycloak extensions
🧯 If You Can't Patch
- Implement network segmentation to isolate Keycloak from sensitive organizational resources
- Enable detailed logging and monitoring for suspicious invitation token usage patterns
🔍 How to Verify
Check if Vulnerable:
Check if your Keycloak version matches affected versions in RHSA-2026:2364 and test invitation token modificationCheck Version:
keycloak/bin/kc.sh --version or check Keycloak admin console version informationVerify Fix Applied:
After patching, attempt to modify an invitation token's organization ID and email - this should now fail with proper signature verification📡 Detection & Monitoring
Log Indicators:
- Unusual organization membership changes
- Invitation token usage from unexpected sources
- Failed token validation attempts
Network Indicators:
- Unexpected authentication requests with modified token parameters
SIEM Query:
source="keycloak" AND (event_type="INVITATION_ACCEPTED" OR event_type="ORGANIZATION_JOIN") AND organization_id_changed=true