Apache bRPC up to 1.17.x Redis server command parser ConsumeImpl out-of-bounds write

Summaryinfo

A vulnerability was found in Apache bRPC up to 1.17.x and classified as critical. The impacted element is the function RedisCommandParser::ConsumeImpl of the component Redis server command parser. Executing a manipulation can lead to out-of-bounds write. This vulnerability is registered as CVE-2026-56388. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Apache bRPC up to 1.17.x and classified as critical. This vulnerability affects the function RedisCommandParser::ConsumeImpl of the component Redis server command parser. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect integrity, and availability. CVE summarizes:

The Redis server command parser in Apache bRPC accepts an empty RESP array as a command header. A remote unauthenticated attacker who can reach a bRPC server with Redis service enabled can send an empty array header followed by a bulk string, causing an out-of-bounds write in the parser and crashing the process. Root Cause: RedisCommandParser::ConsumeImpl rejected negative RESP array counts but accepted zero. It resized the command argument vector to zero elements and continued parsing. When a following bulk string was parsed, the only index guard was a CHECK. In configurations where fatal logs do not abort immediately, execution could continue and write to _args[0] even though the vector was empty. Affected Scenarios: Deployments that enable ServerOptions.redis_service and accept Redis protocol traffic from untrusted clients. The issue is reached during parsing before command handling or authentication. How to Fix: 1. Upgrade bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3354 Note: The fix rejects empty RESP arrays as invalid Redis commands and replaces the internal index CHECK with an explicit parse error so malformed command streams cannot fall through to an indexed vector write.

The advisory is available at lists.apache.org. This vulnerability was named CVE-2026-56388 since 06/21/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 10/21/2026).

Upgrading to version 1.18.0 eliminates this vulnerability. Applying the patch pull/3354 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Vendor

• Apache

Name

• bRPC

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17

License

• open-source

Website

• Vendor: https://www.apache.org/

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