CVE-2026-56388: Apache bRPC: Out-of-Bounds Write in Redis Command Parser

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 30 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

1%

Up from 0.3% on 24 Oct 2026.

EPSS score, percentile 61.4 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

9.1 Critical

CVSS v3.1 base score, from CISA's enrichment of the record

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

• before 1.18.0

Versions by product

Source: CISA KEV 2026.10.30, as of 30 Oct 2026; FIRST EPSS, as of 31 Oct 2026; CVE List, as of 1 Nov 2026. About the data.

Description

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

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.

Source: CVE List, as of 1 Nov 2026. About the data.

What to do

Advisories and patches

• lists.apache.org (Vendor advisory)

This summary is based on the CVE record as of 1 Nov 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 1 Nov 2026. About the data.

Timeline

Known exploited Apache vulnerabilities

• CVE-2016-3081: Apache Struts Command Injection Vulnerability (added 8 Oct 2026)
• CVE-2026-34486: Apache Tomcat Missing Encryption of Sensitive Data Vulnerability (added 4 Aug 2026)
• CVE-2026-34197: Apache ActiveMQ Improper Input Validation Vulnerability (added 16 Apr 2026)
• CVE-2024-38475: Apache HTTP Server Improper Escaping of Output Vulnerability (added 1 May 2025)
• CVE-2025-24813: Apache Tomcat Path Equivalence Vulnerability (added 1 Apr 2025)