Authenticated server crash via TLS list use-after-free
Published Aug 18, 2026 · Updated Aug 19, 2026
Use-after-free in Valkey before 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1 allows remote authenticated users to crash the server via TLS. In src/tls.c, tlsProcessPendingData walks pending_list with a cached next pointer while CLIENT KILL can close another TLS connection and let connTLSClose delete that next node, so the next list access dereferences freed memory. Only TLS-enabled deployments are affected, and exploitation requires an authenticated client able to issue CLIENT KILL; the published advisory describes server crash as the demonstrated result and remote code execution only as a potential consequence with heap grooming.
Summary
What happened
Use-after-free in Valkey before 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1 allows remote authenticated users to crash the server via TLS. In src/tls.c, tlsProcessPendingData walks pending_list with a cached next pointer while CLIENT KILL can close another TLS connection and let connTLSClose delete that next node, so the next list access dereferences freed memory. Only TLS-enabled deployments are affected, and exploitation requires an authenticated client able to issue CLIENT KILL; the published advisory describes server crash as the demonstrated result and remote code execution only as a potential consequence with heap grooming.
The record
- CVE
- CVE-2026-56684
- Published
- Aug 18, 2026
- Updated
- Aug 19, 2026
- Vendor
- Valkey
- Product
- Valkey
- Classifications
- CWE-416, T1210
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 18, 2026CVE publishedPublication date reported by the CVE source.
- Aug 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 7.2.14
- Affected versionversion=>= 8.0.0, < 8.0.10
- Affected versionversion=>= 8.1.0, < 8.1.9
- Affected versionversion=>= 9.0.0, < 9.0.5
- Affected versionversion=>= 9.1.0, < 9.1.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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