CVE-2026-76827 Search-indexer: search-indexer: update/delete operations not scoped to caller's cluster (cross-tenant data tampering)
Authenticated managed clusters can tamper with or delete other clusters' indexed search data due to missing ownership checks in write operations.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-76827?
CVE-2026-76827 is a medium-severity missing authorization vulnerability in Red Hat Advanced Cluster Management for Kubernetes 2.11, published on 19 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
A flaw was found in search-indexer. This vulnerability allows a registered and authenticated managed cluster to tamper with or delete another cluster's indexed search data. This is possible because 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.
Weakness: CWE-693
Which versions are affected by CVE-2026-76827?
How do I fix CVE-2026-76827?
No fix has been published for CVE-2026-76827 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-76827 being exploited?
There is no known exploitation of CVE-2026-76827 in the wild and no public exploit code.
Sources
Also known as GHSA-4vrw-8fx2-pj82.