---
title: "Istio / ISTIO-SECURITY-2026-005"
url: https://daily.dev/posts/istio-istio-security-2026-005-1tnumumha
source_url: https://istio.io/latest/news/security/istio-security-2026-005
type: article
source: "Istio"
published: 2026-06-24T18:25:42.367Z
updated: 2026-06-24T18:26:09.080Z
tags: ["security", "istio", "service-mesh", "envoy"]
reading_time: 3
upvotes: 0
comments: 0
language: en
---

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# Istio / ISTIO-SECURITY-2026-005

**[Istio](https://daily.dev/sources/istio)** · 3 min read · 0 upvotes · 0 comments

## Summary

Istio security advisory ISTIO-SECURITY-2026-005 discloses multiple CVEs affecting Envoy and Istio, with patches available in versions 1.29.5 and 1.28.9. Envoy fixes include a denial-of-service via HTTP/3 QPACK blocked decoding (CVSS 7.5), a PROXY protocol header smuggling bug (CVSS 4.8), a use-after-free in the ext_authz filter (CVSS 5.9), a memory exhaustion in the Zstd decompressor (CVSS 7.5), a padding oracle in the OAuth2 filter's AES-256-CBC cookie decryption (CVSS 6.8), SAN validation bypass via embedded NUL bytes (CVSS 4.4), and several crash/use-after-free bugs across HTTP/3, ext_proc, gRPC stats, and DNS query handling.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://istio.io/latest/news/security/istio-security-2026-005>

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---

Tags: [#security](https://daily.dev/tags/security), [#istio](https://daily.dev/tags/istio), [#service-mesh](https://daily.dev/tags/service-mesh), [#envoy](https://daily.dev/tags/envoy)

[View this post on daily.dev](https://daily.dev/posts/istio-istio-security-2026-005-1tnumumha)