Announcing Istio 1.26.3

Istio 1.26.3 patch release.

Jul 29, 2025

This release contains bug fixes to improve robustness. This release note describes what’s different between Istio 1.26.2 and 1.26.3.

Things to know and prepare before upgrading.

Download and install this release.

Visit the documentation for this release.

Inspect the full set of source code changes.

Changes

Fixed ambient index to filter configs by revision. (Issue #56477)
Fixed an issue where the topology.istio.io/network label was not properly skipped on the system namespace when discoverySelectors were in use. (Issue #56687)
Fixed an issue where the CNI plugin incorrectly handled pod deletion when the pod was not yet marked as enrolled in the mesh. In some cases, this could cause a pod, which had been deleted, to be included in the ZDS snapshot and never cleaned up. If this occurred, ztunnel would not be able to become ready. (Issue #56738)
Fixed an issue where access logs were not updated when the referenced service was created later than the Telemetry resource. (Issue #56825)
Fixed an issue where ClusterTrustBundle was not configured properly when ENABLE_CLUSTER_TRUST_BUNDLE_API was enabled.
Fixed an issue where Istio access logs were never sent to the OTLP endpoint. (Issue 56825)
Fixed an issue where high CPU usage could occur if an item was actively being worked on by a different worker until that worker was done with that item.