High8.8Red Hat Linux

High [CVE-2026-63639] Remote code execution via use-after-free in stream deserialization

This high-severity Red Hat Linux advisory covers CVE-2026-63639 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat package: valkey.

CVE-2026-63639 Published Aug 18, 2026Updated by vendor Aug 18, 2026

CVE-2026-63639

Affected products & platforms

Red Hat LinuxRed Hat Enterprise Linux

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Summary

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. This occurs when a malformed data stream is processed during stream deserialization, causing a shared resource to be improperly managed.

If successfully exploited, this flaw could lead to remote code execution. Red Hat severity: Important — CVSS 8.8 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Weakness: CWE-825. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 9.

Red Hat does not currently list a fixing RHSA for this CVE.

Affected products named by the advisory: Red Hat package: valkey.

Affected versions

< 7.2.14
< 8.0.10
< 8.1.9
< 9.0.5
< 9.1.1

Official advisory · high-confidence parse· fetched 2 hours ago·verify at source

Fixed versions

7.2.14
8.0.10
8.1.9
9.0.5
9.1.1

Official advisory · high-confidence parse· fetched 2 hours ago·verify at source

Mitigation checklist

Recommended fix / mitigation

To mitigate this issue, restrict network access to the Valkey instance to only trusted clients and networks. This limits an attacker's ability to send malformed RDB stream payloads to the RESTORE command. Implement firewall rules to block unauthorized access to the Valkey port.

Official advisory · high-confidence parse· fetched 2 hours ago·verify at source

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