Unscored severity · published Oct 21, 2026
CVE-2026-56388
Apache bRPC: Out-of-Bounds Write in Redis Command Parser
New
–
CVSS
0.3%
EPSS
No
On KEV
Description
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AB
Apache bRPC · Apache Software Foundation
before 1.18.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56388
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-56388
lists.apache.org
https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb
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