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TI-2026-78754 Aliases CVE-2026-84748GHSA-qxr6-5hxr-grrc

Builtin services reachable via public port in Apache bRPC

Priority LOW 39CWE-285Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-285.

Summary

Apache bRPC versions before 1.18.0 fail to enforce authorization on protobuf-based protocols, so remote attackers can reach builtin services through the public port. The flaw is an improper authorization issue (CWE-285) in the dispatch of baidu_std, hulu_pbrpc, sofa_pbrpc and several nshead-based protocols. An unauthenticated remote attacker who can reach the public port can invoke builtin services such as brpc.vars and hotspots to read runtime metrics, flags and profiler data that the operator meant to expose only on the internal port.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

Improper authorization in Apache bRPC (versions < 1.18.0) on all platforms allows remote attackers to access builtin services through the public port. Root Cause: ServerOptions.internal_port is documented to make builtin services (and Tabbed services) reachable only from the internal port, and the HTTP/h2 dispatch path enforced this. However, all protobuf-based protocol dispatch paths (baidu_std, hulu_pbrpc, sofa_pbrpc, and the nshead-based protocols public_pbrpc, nshead_mcpack, nova_pbrpc and ubrpc2pb) computed the security_mode flag but never enforced it between method resolution and method invocation. Since builtin services share the method map with user services, a client able to reach the public port could invoke builtin services such as brpc.vars or hotspots by name over these pb protocols and disclose sensitive runtime information (metrics, flags, profiler data) that the operator intended to expose only via the internal port. Affected Scenarios: Use a bRPC server with ServerOptions.internal_port configured (or with builtin/Tabbed services otherwise expected to be gated by it) while the public port is reachable from an untrusted network and any pb-based protocol is enabled. How to Fix: (Choose one of the following options)  1. Upgrade bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3511

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00426 37th percentileScored 2026-11-07
Fix Fixed Apache bRPC (Apache Software Foundation): 1.18.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ApacheApache bRPCbefore 1.18.01.18.0Patch availableCNA
  • Apache bRPC VendorApache Affected before 1.18.0 Fixed in 1.18.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:apache:brpc:*:*:*:*:*:*:*:*——Apache
  • cpe:2.3:a:apache:brpc:*:*:*:*:*:*:*:* Versions — — ·Apache

Remediation

Upgrade Apache bRPC to version 1.18.0, which fixes this issue. A patch is also available from the project's pull request 3511 on GitHub.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

  • Fix · CNA Apache bRPC (Apache Software Foundation) Fixed in 1.18.0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Apache bRPC — lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb

    35 records Highest priority Priority MEDIUM 18 MEDIUM, 17 LOW

    Other records, highest priority first

    • TI-2026-78552 Out-of-bounds write in Apache bRPC Redis command parserPriority MEDIUM 49
    • TI-2026-78757 Authentication bypass in Apache bRPC servers using internal_portPriority MEDIUM 48
    • TI-2026-78742 Missing authentication in Apache bRPC streaming RPC framesPriority MEDIUM 48
    Show all 35 records → Advisory →

Timeline

  1. 2026-10-21 Threatist record created from CVE-2026-84748
  2. 2026-10-21 Alias added: GHSA-qxr6-5hxr-grrc
  3. 2026-10-30 CVSS score added · CISA ADP
  4. 2026-10-30 CISA SSVC decision points changed

References

Advisory 1

  • TI-2025-18529 Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT KEVCVSS 3.1CRITICAL 10.0
  • TI-2024-30292 Apache OFBiz: Confused controller-view authorization logic (forced browsing) KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-26062 Apache OFBiz: Unauthenticated endpoint could allow execution of screen rendering code KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-21190 Apache OFBiz: Path traversal leading to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-18186 Apache HugeGraph-Server: Command execution in gremlin KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-25106 Deserialization of untrusted data in Apache ActiveMQ KEVCVSS 3.1CRITICAL 10.0
See all 4053 →

Sources

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