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Fencer Vulns
high 7.5

CVE-2026-74758 json

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

published 2026-10-21 19 d ago modified 2026-10-30 9 d ago also EUVD-2026-107182

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

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.

Patch / fix

  • Apache Software Foundation Apache bRPC 1.18.0

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
9 d ago

Exploit prediction

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Apache Software Foundation Apache bRPC

Classification

Weakness

References

Sources

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