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CVE-2026-54427

Apache bRPC: Stack Exhaustion via Unbounded Recursion in AMF Parser

Apache Software Foundation Apache bRPCFrameworks
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.16%Chance of exploitation activity in the next 30 days, higher than 5% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in1.18.0Fixed versionCVE List
Published21 Oct 2026Updated 21 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

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.

Text from CVE List

Affected versions 1

  • Apache bRPCaffected: all versions before 1.18.0CVE List

References 1