52/69 Wednesday, January 28, 2026
Cloudflare has released details about a BGP route leak that occurred on January 22, impacting IPv6 traffic for approximately 25 minutes. The incident caused significant network congestion and packet loss, with traffic drops reaching up to 12 Gbps. The impact was not limited to Cloudflare customers but also affected interconnected external networks.
Technical analysis revealed that the root cause was a policy misconfiguration on a router during an attempted update to routing announcements. This misconfiguration inadvertently allowed internal routes to be advertised to peers and upstream providers, constituting Type 3 and Type 4 route leaks as defined in RFC 7908. The incident violated valley-free routing principles, causing traffic to be forwarded along unsupported paths or dropped by downstream networks’ security controls, ultimately resulting in packet loss.
Cloudflare engineers detected the anomaly quickly and resolved the issue by rolling back the configuration, restoring normal operations within a short time frame. Cloudflare acknowledged similarities to a previous incident in July 2020 and stated that additional safeguards have since been implemented, including stricter validation in CI/CD pipelines and stronger advocacy for broader adoption of RPKI ASPA security standards to help prevent similar incidents in the future.
