Unbounded recursion in Apache bRPC AMF parser exhausts stack
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-674.
Summary
Apache bRPC before 1.18.0 recursively parses nested AMF containers in its RTMP support without enforcing a depth limit (CWE-674). A remote RTMP peer that needs no privileges or user interaction can send deeply nested AMF objects or arrays to exhaust the native stack and crash the bRPC process.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
Uncontrolled recursion in the AMF parser in Apache bRPC < 1.18.0 allows a remote RTMP peer to crash a bRPC process by sending deeply nested AMF objects or arrays. The parser recursively processed nested AMF containers without enforcing a depth limit, which could exhaust the native stack. Affected Scenarios: Applications using bRPC RTMP support and parsing AMF data from an untrusted RTMP peer. This includes RTMP servers parsing client command messages, RTMP clients parsing server responses or status messages, and either side parsing inbound AMF script data such as metadata or cue points. Direct callers of ReadAMFObject or ReadAMFArray on untrusted input are also affected. How to Fix: 1. Upgrade Apache bRPC to 1.18.0. 2. Apply the patch from PR https://github.com/apache/brpc/pull/3344 . Note: The fix introduces a configurable AMF nesting depth limit with default value 128. AMF objects or arrays deeper than amf_max_depth are rejected after applying the fix.
Why it matters now
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
Remediation
Upgrade Apache bRPC to version 1.18.0, or apply the patch from pull request 3344 in the apache/brpc repository. The fix adds a configurable AMF nesting depth limit, amf_max_depth, with a default of 128.
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
Timeline
- 2026-10-21 Threatist record created from CVE-2026-54427
- 2026-10-21 Alias added: GHSA-73m6-hpcv-jggj
- 2026-10-30 CVSS score added · CISA ADP
- 2026-10-30 CISA SSVC decision points changed
References
More Apache vulnerabilities
- 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
Sources
- CVE-2026-54427 · CVE Program
- CVE-2026-54427 · NVD
- FIRST EPSS
- GHSA-73m6-hpcv-jggj · GitHub Advisory Database · CC BY 4.0
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