Null pointer dereference in Apache bRPC MySQL parser crashes client
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-476.
Summary
Apache bRPC versions <= 1.11.0 (before 1.18.0) are affected. The MySQL client response parser dereferences a null pointer when a server sends a zero-length response packet (CWE-476). A malicious or compromised MySQL server, or a man-in-the-middle, can crash the client process with such a packet, causing denial of service.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
The MySQL client response parser in Apache bRPC dereferences a null pointer when the server peer sends a zero-payload-length response packet. A response packet whose declared payload length is zero is accepted by the frame-length check (is_full_package), after which the parser reads the response type byte via an unbounded 5-byte fetch that returns nullptr, and type = p[4] dereferences it, crashing the client process. Root Cause: In brpc::policy::MysqlReply::ConsumePartialIOBuf, buf.fetch(header, 5) returns nullptr when the buffered data only holds the 4-byte header of a zero-length packet, then the code reads p[4] (and, in the fast-auth path, p2[4]) without checking for a null or zero-length packet. Affected Scenarios: A brpc MySQL client connecting to a malicious or compromised MySQL server (or a MITM) can be crashed by a zero-length server response packet, resulting in denial of service of the client. Fix: The fix rejects zero-length response packets (returning PARSE_ERROR_ABSOLUTELY_WRONG) both for the initial response type determination and after a fast-auth marker, before reading the type byte. Upgrade to the Apache bRPC version 1.18.0 or apply the PR patch at https://github.com/apache/brpc/pull/3536.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade to Apache bRPC 1.18.0. Alternatively, apply the patch in pull request 3536 of the apache/brpc repository on GitHub.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- 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-2026-78552 Out-of-bounds write in Apache bRPC Redis command parserPriority MEDIUM 49
- 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
Timeline
- 2026-10-21 Threatist record created from CVE-2026-90484
- 2026-10-21 Alias added: GHSA-rf6j-677g-5547
- 2026-10-26 CVSS score added · CISA ADP
- 2026-10-26 CISA SSVC decision points changed
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-2026-90484 · CVE Program
- CVE-2026-90484 · NVD
- FIRST EPSS
- GHSA-rf6j-677g-5547 · GitHub Advisory Database · CC BY 4.0
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