Announcing Istio 1.29.1

This release contains security fixes. This release note describes what’s different between Istio 1.29.0 and 1.29.1.

Security update

For more information, see ISTIO-SECURITY-2026-001.

Envoy CVEs

• CVE-2026-26308 (CVSS score 7.5, High): Fix multivalue header bypass in RBAC.
• CVE-2026-26311 (CVSS score 5.9, Medium): HTTP decode methods blocked after downstream reset.
• CVE-2026-26310 (CVSS score 5.9, Medium): Fix crash in getAddressWithPort() with scoped IPv6 address.
• CVE-2026-26309 (CVSS score 5.3, Medium): JSON off-by-one write fix.
• CVE-2026-26330 (CVSS score 5.3, Medium): Ratelimit response phase crash fix.

Istio CVEs

• CVE-2026-31838 / GHSA-974c-2wxh-g4ww: (CVSS score 6.9, Medium): Debug Endpoints Allow Cross-Namespace Proxy Data Access. Reported by 1seal.
• CVE-2026-31837 / GHSA-v75c-crr9-733c: (CVSS score 8.7, High): JWKS Resolver Failure May Allow Authentication Bypass Using Known Default Keys. Reported by 1seal.

Istio Security Fixes

• Fixed XDS debug endpoints on plaintext port 15010 to require authentication, preventing unauthenticated access to proxy configuration. Reported by 1seal.
• Fixed HTTP debug endpoints on port 15014 to enforce namespace-based authorization, preventing cross-namespace proxy data access. Reported by Sergey Kanibor (Luntry).
• Added the ability to specify authorized namespaces for debug endpoints when ENABLE_DEBUG_ENDPOINT_AUTH=true. Enable by setting DEBUG_ENDPOINT_AUTH_ALLOWED_NAMESPACES to a comma separated list of authorized namespaces. The system namespace (typically istio-system) is always authorized.
• Fixed JWKS resolver to use a safe fallback when JWKS fetch fails, preventing authentication bypass via publicly known default keys. Reported by 1seal.
• Fixed potential SSRF in WasmPlugin image fetching by validating bearer token realm URLs. Reported by Sergey Kanibor (Luntry).

Changes

• Fixed incorrect mapping of meshConfig.tlsDefaults.minProtocolVersion to tls_minimum_protocol_version in downstream TLS context.
• Fixed Gateway API CORS origin parsing to be stricter with wildcards, and to ignore unmatched preflights. (Issue #59018)
• Fixed an issue where waypoints failed to add the TLS inspector listener filter when only TLS ports existed, causing SNI-based routing to fail for wildcard ServiceEntry with resolution: DYNAMIC_DNS. (Issue #59024)
• Fixed an issue where baggage-based peer metadata discovery interfered with TLS or PROXY traffic policies. As a short term fix, baggage-based metadata discovery is disabled for routes with TLS or PROXY traffic policies configured, which may result in incomplete telemetry in multicluster deployments. (Issue #59117)
• Fixed a nil pointer dereference that occurs during the upgrade process in multi-primary deployment. (Issue #59153)
• Fixed a nil pointer dereference in ServiceEntry validation for DYNAMIC_DNS resolution that could crash istiod. (Issue #59171)
• Fixed istiod crashing when PILOT_ENABLE_AMBIENT=true but AMBIENT_ENABLE_MULTI_NETWORK is not set and a WorkloadEntry resource exists with a different network than the local cluster.
• Fixed an issue where setting resource limits or requests to null would cause validation errors. (Issue #58805)