Out-of-bounds write in Apache bRPC Redis command parser
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-617.
Summary
Apache bRPC before 1.18.0 has an out-of-bounds write in its Redis command parser (CWE-787). The parser accepts an empty RESP array as a command header, so a following bulk string writes into an empty argument vector. A remote unauthenticated attacker who can reach a server with the Redis service enabled can crash the process.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade Apache bRPC to version 1.18.0, which fixes this issue. Alternatively, apply the patch from Apache bRPC pull request 3354.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
- Fix · CNA Apache bRPC (Apache Software Foundation) Fixed in 1.18.0
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Apache bRPC — lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb
35 records Highest priority Priority MEDIUM 18 MEDIUM, 17 LOW
Other records, highest priority first
- TI-2026-78757 Authentication bypass in Apache bRPC servers using internal_portPriority MEDIUM 48
- TI-2026-78742 Missing authentication in Apache bRPC streaming RPC framesPriority MEDIUM 48
- TI-2026-78545 Authentication bypass in Apache bRPC via builtin HTTP requestsPriority MEDIUM 48
Timeline
- 2026-10-21 Threatist record created from CVE-2026-56388
- 2026-10-21 Alias added: GHSA-57w6-4hvp-7m4g
- 2026-10-30 CVSS score added · CISA ADP
- 2026-10-30 CISA SSVC decision points changed
- 2026-10-30 Priority changed: LOW → MEDIUM
- 2026-10-31 EPSS moved to the 50th–90th percentile
References
More Apache vulnerabilities
- TI-2025-18529 Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT KEVCVSS 3.1CRITICAL 10.0
- TI-2024-30292 Apache OFBiz: Confused controller-view authorization logic (forced browsing) KEVCVSS 3.1CRITICAL 9.8
- TI-2024-26062 Apache OFBiz: Unauthenticated endpoint could allow execution of screen rendering code KEVCVSS 3.1CRITICAL 9.8
- TI-2024-21190 Apache OFBiz: Path traversal leading to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2024-18186 Apache HugeGraph-Server: Command execution in gremlin KEVCVSS 3.1CRITICAL 9.8
- TI-2023-25106 Deserialization of untrusted data in Apache ActiveMQ KEVCVSS 3.1CRITICAL 10.0
Sources
- CVE-2026-56388 · CVE Program
- CVE-2026-56388 · NVD
- FIRST EPSS
- GHSA-57w6-4hvp-7m4g · GitHub Advisory Database · CC BY 4.0
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