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No exploitation reported

CVE-2026-56388

Apache bRPC: Out-of-Bounds Write in Redis Command Parser

No exploitation reported by the sources we read.

  • Published2026-10-21
  • WeaknessCWE-252 · CWE-617 · CWE-787

Am I affected?

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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.

Timeline

dates in UTC
  1. 2026-10-2112:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-31 15:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-56388?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-56388?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-56388 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionnone2026-10-30
  • OpenCVESSVC decisionnone—
  • CISA-ADPCVSS 3.19.12026-10-30
  • CNAweakness (CWE)CWE-252, CWE-617, CWE-787read 2026-10-31
  • NVDweakness (CWE)CWE-252, CWE-617, CWE-787read 2026-10-27
  • FIRST EPSSEPSS score0.3 %2026-10-30

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Published
2026-10-21
Last Modified
2026-10-30
NVD status
Deferred

Frequently asked questions

What is CVE-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 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.

Is CVE-2026-56388 actively exploited?

Active exploitation of CVE-2026-56388 has not been confirmed. Its EPSS score was 0.3% on 2026-10-30, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-56388?

CVE-2026-56388 has a CVSS v3 base score of 9.1 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

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