Apache bRPC: Out-of-bounds read via non-object fields in Discovery naming-service reply parsing
Summary
| CVE | CVE-2026-87849 |
|---|---|
| State | PUBLISHED |
| Assigner | apache |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-21 13:20:04 UTC |
| Updated | 2026-10-21 13:20:04 UTC |
| Description | The Discovery naming-service reply parser in Apache bRPC (versions < 1.18.0) calls RapidJSON object-only accessors (FindMember) on JSON values without first validating that those values are objects. A malformed Discovery response whose data/service members or instances list contain non-object entries (e.g. a bare integer) triggers the RapidJSON object-access precondition on the client, reading memory out of bounds and potentially crashing the bRPC client. Root Cause: In src/brpc/policy/discovery_naming_service.cpp, DiscoveryNamingService::GetServers() and DiscoveryNames::ListDiscoveryNodes() access JSON values with member functions on non-object values. RapidJSON only defines these operations for object types; invoking them on a non-object violates the class invariant and results in undefined behavior (out-of-bounds read), commonly crashing the process. Affected Scenarios: An operator-configured (or compromised) Discovery backend returns a malformed /discovery/nodes or /discovery/fetchs response whose data/service/instance entries are not JSON objects, crashing any bRPC client that refreshes its server list. How to Fix: 1. Upgrade bRPC to version 1.18.0 or later, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3533 The fix validates that the Discovery response data, per-service data, and instance entries are JSON objects (and skips non-object node/instance entries and rejects non-object data/service values) before calling member accessors. |
Risk And Classification
Problem Types: CWE-125 | CWE-125 CWE-125 Out-of-bounds Read
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Apache Software Foundation | Apache BRPC | affected 1.18.0 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb | [email protected] | lists.apache.org | |
| github.com/apache/brpc/pull/3533 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Claude (en)
There are currently no legacy QID mappings associated with this CVE.