{"id":"CVE-2026-90484","title":"Apache bRPC: Null pointer dereference in MySQL reply parser leading to client crash","summary":"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 (…","severity":"none","cwe":["CWE-476"],"vendor":"Apache Software Foundation","product":"apache/brpc","affected":["apache/brpc >= <= 1.11.0 < 1.18.0"],"published":"2026-10-21","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:19:37.796Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-90484","references":[{"url":"https://github.com/apache/brpc/pull/3536","label":"PR 3536"},{"url":"https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb"}],"tags":["cve.org"],"ingestedAt":"2026-10-21T12:48:53.754Z","slug":"CVE-2026-90484","body":"## Overview\n\nThe 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.\n\n\n\nRoot 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.\n\n\n\nAffected 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.\n\n\n\nFix: 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.\n\n## Affected\n\n- `apache/brpc >= <= 1.11.0 < 1.18.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}