CVE-2026-76827 Red Hat CVE debrief

Who should care

Cluster administrators, security teams, and users with access to search-indexer should be aware of this vulnerability. Cluster administrators should review cluster authentication and authorization. Security teams should monitor for suspicious search data modifications. Users with access to search-indexer should be aware of potential tampering or deletion of indexed search data from another cluster.

Technical summary

The delta-sync write paths in search-indexer do not properly restrict UPDATE/DELETE operations to data owned by the calling cluster. An attacker could exploit this by crafting specific user identifiers (UIDs) with a different cluster's prefix. This vulnerability allows a registered and authenticated managed cluster to tamper with or delete another cluster's indexed search data. Cluster administrators should review cluster authentication and authorization. Security teams should monitor for suspicious search data modifications. Users with access to search-indexer should be aware of potential tampering or deletion of indexed search data from another cluster.

Defensive priority

Authenticated cluster users may tamper with or delete indexed search data from another cluster. Review cluster authentication and authorization.

Recommended defensive actions

• Review cluster authentication and authorization
• Verify cluster user access controls
• Monitor for suspicious search data modifications
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

Evidence is limited; verify with vendor. Official CVE and NVD records provide some detail. Red Hat references exist but require authentication. To verify, cluster administrators should review cluster authentication and authorization. Security teams should monitor for suspicious search data modifications. Users with access to search-indexer should be aware of potential tampering or deletion of indexed search data from another cluster.

Official resources