Redis is an in-memory data structure store. In redis-server from 7.2.0 until 8.6.3, the unblock client flow does not handle an error return from processCommandAndResetClient when re-executing a blocked command. If a blocked client is evicted during this flow, an authenticated attacker can trigger a use-after-free that may lead to remote code execution. This has been patched in version 8.6.3.
Weakness
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Redis | Redis | 7.2.0 (including) | 8.6.3 (excluding) |
| Red Hat Enterprise Linux 10 | RedHat | valkey-0:8.0.9-1.el10_2 | * |
| Red Hat Enterprise Linux 10.0 Extended Update Support | RedHat | valkey-0:8.0.9-1.el10_0 | * |
| Red Hat Enterprise Linux 9 | RedHat | redis:7-9080020260521083756.9 | * |
| Red Hat Enterprise Linux 9 | RedHat | valkey-0:8.0.9-1.el9_8 | * |
| Red Hat Enterprise Linux 9.6 Extended Update Support | RedHat | redis:7-9060020260602115714.9 | * |
| Redis | Ubuntu | esm-apps/xenial | * |
| Redis | Ubuntu | questing | * |
Potential Mitigations
References
- https://github.com/redis/redis/releases/tag/8.6.3
- https://github.com/redis/redis/security/advisories/GHSA-93m2-935m-8rj3
- https://access.redhat.com/errata/RHSA-2026:25216
- https://access.redhat.com/errata/RHSA-2026:25219
- https://access.redhat.com/errata/RHSA-2026:25925
- https://access.redhat.com/errata/RHSA-2026:26306
- https://access.redhat.com/errata/RHSA-2026:26540
- https://access.redhat.com/security/cve/CVE-2026-23479
- https://bugzilla.redhat.com/show_bug.cgi?id=2466780
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23479.json