CVE-2026-56684: valkey-io valkey Use After Free

Vulnerability summary

CVE-2026-56684 is a high (CVSS 7.5) Use After Free vulnerability in valkey-io valkey. EPSS estimates a 0.89% chance of exploitation in the next 30 days, higher than 58.6% of scored vulnerabilities.

Timeline

1. 18-08-2026
   PublishedVulnerability first disclosed.
2. 19-08-2026
   Last modifiedVulnerability information updated.

Description

Valkey is a distributed key-value database. Prior to 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1, Valkey's tlsProcessPendingData function iterates pending_list while an authenticated client can trigger CLIENT KILL, causing connTLSClose to delete the iterator's cached next node and producing a use-after-free that can crash the server or potentially allow remote code execution when TLS is enabled. This issue is fixed in versions 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1.

• CWE-416Use After FreeThe 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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.