Nimble Streamer SRT Package Updated with libsrt 1.5.6 Security Fixes

We’ve just released an updated nimble-srt-1.5 package for Nimble Streamer. This update includes libsrt 1.5.6, the latest SRT protocol library release with fixes for two critical security vulnerabilities reported by the SRT Alliance.

The vulnerabilities are registered as CVE-2026-55869, a heap-based buffer overflow in KMREQ handling, and CVE-2026-55868, an encryption state machine downgrade issue. According to the SRT Alliance notification, both issues have a CVSS score of 9.1, so we recommend installing the updated package as soon as possible on Nimble Streamer servers that use SRT.

SRT is widely used for reliable, low-latency live video delivery over unpredictable networks. Updating the SRT library is important for protecting ingest, contribution, and distribution workflows.

The updated nimble-srt-1.5 package is available in all Nimble Streamer package repositories. The update is designed to preserve existing SRT interoperability, so no workflow changes are expected from the library update itself. Operators can upgrade endpoints gradually while keeping current SRT connections compatible.

How to update

For Ubuntu and Debian:

sudo apt-get update
sudo apt-get install nimble-srt-1.5
sudo service nimble restart

For Rocky Linux, AlmaLinux, and other DNF-based systems:

sudo dnf update
sudo dnf install nimble-srt-1.5
sudo systemctl restart nimble

For CentOS and other YUM-based systems:

sudo yum update
sudo yum install nimble-srt-1.5
sudo service nimble restart

Restarting Nimble Streamer is required for the updated SRT library to be loaded.

For general installation and update instructions, see the SRT package installation guide for Nimble Streamer.