rsyslog Windows Agent 26.11 Technical Release Notes
Release date: November 3, 2026
Service build: 26.11.0.357
Configuration Client build: 26.11.0.446
User Interface build: 26.11.0.1020
Upgrade assessment
Recommendation: Recommended update
Why update now: This release adds manual hostname mappings. It also verifies TLS and DTLS destinations, rejects malformed Syslog headers, and corrects remote configuration, licensing, and service diagnostics.
If you defer: Existing processing continues, but hostname mappings and the Syslog, TLS, remote-configuration, and diagnostic corrections in this release remain absent.
Who benefits most: Administrators who map hostnames, receive Syslog, or forward over TLS or DTLS.
Upgrade and verification: Update rsyslog Windows Agent using the normal supported upgrade path. Confirm that the installed service version is 26.11.0.357. Test the changed functions that are relevant to your deployment.
Important changes
Hostname and IP mappings
- Change: General settings can define hostname and IP address mappings in the Configuration Client and in the User Interface.
- Operational impact: Events can use a configured hostname or IP address mapping instead of the resolved value alone.
- Applies to: rsyslog Windows Agent installations that resolve hostnames.
- Verification: Add a hostname and IP address mapping, then confirm a processed event uses the mapped value.
TLS and DTLS forwarding
- Change: TLS and DTLS forwarding verify destination certificates and identities. Stalled TLS forwarding no longer blocks shutdown indefinitely.
- Operational impact: A destination with an unexpected certificate or identity is not treated as verified, and a stalled TLS send does not keep the service from shutting down.
- Applies to: rsyslog Windows Agent installations that forward over TLS or DTLS.
- Verification: Exercise one TLS or DTLS forwarding destination you use. Confirm the service shuts down after a TLS send that does not complete promptly.
Syslog Listener
- Change: The Syslog Listener rejects malformed message headers.
- Operational impact: A malformed Syslog header is rejected instead of being processed as a normal message.
- Applies to: rsyslog Windows Agent installations that receive Syslog.
- Verification: In a test environment, confirm a malformed Syslog header is rejected.
Remote configuration, licensing, and diagnostics
- Change: Remote configuration rejects invalid HTTPS certificates and insecure redirects. Registry configuration detects the default license file more reliably when the license path is empty and no separate data directory is configured. If a different data directory is configured, that directory remains the default license location. When a listening socket cannot be opened, diagnostics include possible owners.
- Operational impact: Insecure remote configuration downloads are rejected. The default license file is found for the empty-path registry case described above, and a failed listening socket identifies possible owners.
- Applies to: rsyslog Windows Agent installations that download remote configuration, use registry licensing, or open listening sockets.
- Verification: Confirm an invalid HTTPS certificate or an insecure redirect is rejected when downloading configuration. With an empty license path and no separate data directory, confirm the service finds the default license file. Confirm a failed listening socket reports possible owners.
Configuration Client
- General settings can define hostname and IP address mappings.
- The Syslog action can set the TLS send progress timeout.
- A partial configuration is not saved after loading fails, and existing settings are preserved when a selective import fails.
User Interface
- General settings can define hostname and IP address mappings.
- The Syslog action can set the TLS send progress timeout.
- A partial configuration is not saved after loading fails, and existing settings are preserved when a selective import fails.
- The dashboard displays content in the selected language.
Partner deployment notes
Availability: Use the canonical rsyslog Windows Agent download and this Technical Release Notes page as the release reference; do not use temporary build links as the long-term reference.
Localization: The User Interface translation workflow is being prepared. Translation strings and contribution guidance will be published in the Adiscon community repository when available.
Partner verification: Confirm the installed service, Configuration Client, and User Interface builds. Where relevant, compare a hostname mapping with a processed event and save a configuration change.