Security research · CVE-2026-56388
The Redis server command parser in Apache bRPC accepts an empty RESP array as a command header.
Published Oct 21, 2026 · catalog updated Oct 21, 2026 · Apache Software Foundation Apache bRPC
Last checked Oct 31, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-56388. EPSS is 0.95%. Act only if a listed version of Apache Software Foundation Apache bRPC is installed.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
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- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.95%
- Remediation
- Not established
- Affected products
- vendor Apache Software Foundation Apache bRPC
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.
Are you affected?
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- vendor Apache Software Foundation Apache bRPCversion unspecified
How to fix CVE-2026-56388
No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
No version range is stored, so an installed version cannot be checked on this page.
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-56388. EPSS is 0.95%. Act only if a listed version of Apache Software Foundation Apache bRPC is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-252: Unchecked Return Value; CWE-617; CWE-787: Out-of-bounds Write. EPSS 0.95%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Oct 21, 2026 · NIST NVD
Detected
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 ac
Sources
- CVE.orgVulnerability recordCVE-2026-56388
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
cve.org - FIRST EPSSExploitation probabilityCVE-2026-56388
30-day exploitation probability 0.95%
first.org - NIST NVDVulnerability recordCVE-2026-56388
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
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 31, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSOct 31, 2026
- CVE.orgOct 21, 2026
- NIST NVDOct 21, 2026