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CVE-2026-74758

Apache bRPC: Heap Use-After-Free in RTMP Abort Message Handling

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)0.24%Chance of exploitation activity in the next 30 days, higher than 14% 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

A heap use-after-free in the RTMP protocol component of Apache bRPC (versions < 1.18.0) allows a remote attacker to crash a bRPC RTMP server by sending a crafted Abort control message. No authentication or application-level request is required.

Root Cause: When an RTMP Abort control message names the chunk stream that is currently being parsed (the chunk stream carrying the message itself), RtmpChunkStream::OnAbortMessage calls RtmpContext::ClearChunkStream, which deletes the RtmpChunkStream while its Feed() is still running. After the message handler returns, Feed() continues to access members of the deleted object, resulting in a heap-use-after-free.

Affected Scenarios: bRPC servers that enable RTMP support (ServerOptions.rtmp_service set) and accept connections from untrusted networks.

How to Fix:

  1. Upgrade bRPC to version 1.18.0, which fixes this issue.
  2. Apply this patch:  https://github.com/apache/brpc/pull/3452

The fix skips clearing the chunk stream when the Abort message targets the chunk stream that is currently being parsed.

Text from CVE List

Affected versions 1

  • Apache bRPCaffected: all versions before 1.18.0CVE List

References 1