CVE-2025-59789: Apache bRPC: Stack Exhaustion via Unbounded Recursion in JSON Parser

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-01 · updated 2026-10-18
Weakness: CWE-674

Description

Uncontrolled recursion in the json2pb component in Apache bRPC (version < 1.15.0) on all platforms allows remote attackers to make the server crash via sending deep recursive json data. Root Cause: The bRPC json2pb component uses rapidjson to parse json data from the network. The rapidjson parser uses a recursive parsing method by default. If the input json has a large depth of recursive structure, the parser function may run into stack overflow. Affected Scenarios: Use bRPC server with protobuf message to serve http+json requests from untrusted network. Or directly use JsonToProtoMessage to convert json from untrusted input. How to Fix: (Choose one of the following options) 1. Upgrade bRPC to version 1.15.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3099 Note: No matter which option you choose, you should know that the fix introduces a recursion depth limit with default value 100. It affects these functions: ProtoMessageToJson, ProtoMessageToProtoJson, JsonToProtoMessage, and ProtoJsonToProtoMessage. If your requests contain json or protobuf messages that have a depth exceeding the limit, the request will be failed after applying the fix. You can modify the gflag json2pb_max_recursion_depth to change the limit.

Affected products

Apache Software Foundation Apache bRPC: before 1.15.0 — fixed in 1.15.0

How to fix

Upgrade to a fixed version: Apache Software Foundation Apache bRPC 1.15.0. Check the vendor advisory for mitigations.

References

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