Uncontrolled recursion in the mcpack2pb component in Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to make the server… (CVE-2026-82230)
Description
Apache bRPC versions prior to 1.18.0 contain an uncontrolled recursion vulnerability in the mcpack2pb component. This flaw allows remote attackers to crash the server by sending deeply nested mcpack data. The parser recursively processes nested objects and arrays without a depth limit, leading to stack overflow and process crash. The issue affects bRPC servers handling nshead_mcpack, ubrpc, or public_pbrpc requests with recursive protobuf schemas. The vulnerability is fixed in version 1.18.0 by enforcing a maximum parsing depth of 128 levels.
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The mcpack2pb parser in Apache bRPC versions before 1.18.0 recursively parses nested protobuf messages without limiting recursion depth. For protobuf messages that reference themselves, this unbounded recursion can cause stack overflow and crash the server when processing deeply nested mcpack data. This affects bRPC servers serving nshead_mcpack, ubrpc, or public_pbrpc requests from untrusted networks. The issue is resolved in version 1.18.0 by enforcing a MAX_DEPTH limit of 128 on parsing, preventing unbounded recursion.
Potential Impact
Remote attackers can cause a denial of service by crashing the bRPC server through sending specially crafted deeply nested mcpack data. This leads to stack overflow and process termination, disrupting service availability.
Mitigation Recommendations
Upgrade Apache bRPC to version 1.18.0, which includes an official fix enforcing a maximum parsing depth to prevent uncontrolled recursion. Alternatively, apply the patch available at https://github.com/apache/brpc/pull/3499. After applying the fix, requests with nesting deeper than 128 levels will be rejected.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-5pph-8c9p-w8p3
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-82230"]
- State
- PUBLISHED
Threat ID: 6ad91cd94d27ba8daafaa5c1
Added to database: 10/21/2026, 20:13:13 UTC
Last enriched: 10/21/2026, 20:21:06 UTC
Last updated: 10/21/2026, 22:15:13 UTC
Views: 4
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