Apache bRPC up to 1.17.x RTMP OnAbortMessage use after free

Summaryinfo

A vulnerability was found in Apache bRPC up to 1.17.x and classified as problematic. Affected is the function RtmpChunkStream::OnAbortMessage of the component RTMP. The manipulation results in use after free. This vulnerability is cataloged as CVE-2026-74758. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Apache bRPC up to 1.17.x. Affected is the function RtmpChunkStream::OnAbortMessage of the component RTMP. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is shared for download at lists.apache.org. This vulnerability is traded as CVE-2026-74758 since 08/15/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/21/2026).

Upgrading to version 1.18.0 eliminates this vulnerability. Applying the patch 3452 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Apache

Name

• bRPC

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17

License

• open-source

Website

• Vendor: https://www.apache.org/

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