Authenticated denial of service via multi-bulk allocation
Published Jul 23, 2025 · Updated Aug 26, 2025
Denial of service in Redis 8.0.3 and earlier allows remote authenticated users to exhaust server memory with multi-bulk commands. processMultibulkBuffer allocates each parsed bulk argument before command authorization, so denied commands retain attacker-supplied data until memory is exhausted. Low-privilege authentication is sufficient and ACL denial does not prevent service interruption, although Redis disputes that protocol abuse violates its security model.
Summary
What happened
Denial of service in Redis 8.0.3 and earlier allows remote authenticated users to exhaust server memory with multi-bulk commands. processMultibulkBuffer allocates each parsed bulk argument before command authorization, so denied commands retain attacker-supplied data until memory is exhausted. Low-privilege authentication is sufficient and ACL denial does not prevent service interruption, although Redis disputes that protocol abuse violates its security model.
The record
- CVE
- CVE-2025-46686
- Published
- Jul 23, 2025
- Updated
- Aug 26, 2025
- Vendor
- Redis
- Product
- Redis
- Classifications
- CWE-401, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 23, 2025CVE publishedPublication date reported by the CVE source.
- Aug 26, 2025Record 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=0 <=8.0.3
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- CVE-2025-46686 multi-bulk denial-of-service proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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