Fedora 44 Valkey 9.0.3 Critical RESP Injection and DoS Security Advisory

Valkey is an advanced key-value store. It is often referred to as a data

structure server since keys can contain strings, hashes, lists, sets and

sorted sets.

You can run atomic operations on these types, like appending to a string;

incrementing the value in a hash; pushing to a list; computing set

intersection, union and difference; or getting the member with highest

ranking in a sorted set.

In order to achieve its outstanding performance, Valkey works with an

in-memory dataset. Depending on your use case, you can persist it either

by dumping the dataset to disk every once in a while, or by appending

each command to a log.

Valkey also supports trivial-to-setup master-slave replication, with very

fast non-blocking first synchronization, auto-reconnection on net split

and so forth.

Other features include Transactions, Pub/Sub, Lua scripting, Keys with a

limited time-to-live, and configuration settings to make Valkey behave like

a cache.

You can use Valkey from most programming languages also.

See https://valkey.io/topics/

Valkey 9.0.3 - February 23, 2026 Upgrade urgency SECURITY: This release includes security fixes we recommend you apply as soon as possible. Security fixes (CVE-2025-67733) RESP Protocol Injection via Lua error_reply (CVE-2026-21863) Remote DoS with malformed Valkey Cluster bus message (CVE-2026-27623) Reset request type after handling empty requests Bug fixes Avoids crash during MODULE UNLOAD when ACL rules reference a module command and subcommand (#3160) Fix server assert on ACL LOAD when current user loses permission to channels (#3182) Fix bug causing no response flush sometimes when IO threads are busy (#3205)