Uncontrolled Recursion in Apache bRPC json2pb <1.15.0
CVE-2025-59789 Published on December 1, 2025
Apache bRPC: Stack Exhaustion via Unbounded Recursion in JSON Parser
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.
Vulnerability Analysis
CVE-2025-59789 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Stack Exhaustion Vulnerability?
The product does not properly control the amount of recursion which takes place, consuming excessive resources, such as allocated memory or the program stack.
CVE-2025-59789 has been classified to as a Stack Exhaustion vulnerability or weakness.
Products Associated with CVE-2025-59789
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Affected Versions
Apache Software Foundation Apache bRPC:- Before 1.15.0 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.