CVE-2026-56684 valkey-io CVE debrief

Who should care

Defenders managing Valkey deployments, especially those with TLS enabled, should assess potential exposure and impact. This includes operators, platform administrators, vulnerability management teams, and security teams responsible for Valkey installations. They should prioritize verifying exposure and assessing potential impact, focusing on Valkey deployments with TLS enabled.

Why it matters

Defenders should prioritize verifying exposure and assessing potential impact of the use-after-free vulnerability in Valkey, especially in deployments with TLS enabled.

• Potential server crashes due to use-after-free vulnerability
• Possible remote code execution when TLS is enabled
• Need for verification of Valkey version and exposure
• Potential impact on data integrity and confidentiality

Technical summary

The tlsProcessPendingData function in Valkey iterates over pending_list while an authenticated client can trigger CLIENT KILL, causing connTLSClose to delete the iterator's cached next node, resulting in a use-after-free vulnerability. This can crash the server or potentially allow remote code execution when TLS is enabled. The vulnerability affects Valkey deployments with TLS enabled, and defenders should prioritize verifying exposure and assessing potential impact. The issue is fixed in versions 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1.

Defensive priority

Defenders should prioritize verifying exposure and assessing potential impact, focusing on Valkey deployments with TLS enabled.

Recommended defensive actions

• Verify Valkey version and assess exposure
• Evaluate potential impact of use-after-free vulnerability
• Consider upgrading to fixed versions (7.2.14, 8.0.10, 8.1.9, 9.0.5, or 9.1.1)
• Monitor for potential remote code execution attempts when TLS is enabled
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but specific exploitation or impact instances are not mentioned. The vulnerability affects Valkey versions prior to 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1. Defenders should verify exposure and assess potential impact, focusing on Valkey deployments with TLS enabled. Evidence from the CVE record and NVD entry suggests that the vulnerability can cause server crashes or potentially allow remote code execution when TLS is enabled.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.