Traefik v3.6.15 released on 29-04-2026
Traefik v3.6.15 is out now. It includes a required migration step and dependency bumps (notably the ACME client) that administrators should check before upgrading.
Read the migration guide at https://doc.traefik.io/traefik/migrate/v3/#v3615 and review the release notes on the Traefik GitHub for full details and upgrade guidance.
What’s in this release
- Important migration step — follow the migration guide for configuration and behaviour changes specific to v3.6.15.
- ACME client bumped: github.com/go-acme/lego/v4 updated to v4.35.2 (previously v4.35.1), bringing bug fixes and stability improvements for certificate issuance and renewal.
- Errors middleware adds an errorRequestHeaders option to emit configurable headers on error-generated or forwarded requests.
Upgrade notes
- Read and follow the migration guide at https://doc.traefik.io/traefik/migrate/v3/#v3615 before upgrading to avoid surprises from config or behaviour changes.
- After upgrading, verify Let’s Encrypt / ACME certificate issuance and renewal in staging and production, validate ExternalName service routing (no port now required), and update any CI/build scripts that rely on the FLAGS Make variable.
Share your upgrade experience on the Traefik GitHub or community channels so others know what to watch for.
