CVE-2026-63639: valkey-io valkey Use After Free

Vulnerability summary

CVE-2026-63639 is a high (CVSS 8.8) Use After Free vulnerability in valkey-io valkey. EPSS estimates a 1.17% chance of exploitation in the next 30 days, higher than 66.9% of scored vulnerabilities.

Timeline

1. 18-08-2026
   PublishedVulnerability first disclosed.
2. 20-08-2026
   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 RESTORE command accepts a malformed RDB stream payload that assigns one Pending Entry List NACK to multiple consumers during stream consumer-group deserialization, causing a use-after-free when one consumer is deleted while another still references the shared NACK and potentially allowing remote code execution. 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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.