---
id: "CVE-2026-129485"
page: "https://infrastack.ai/live/CVE-2026-129485"
kind: "vulnerability"
aliases: ["CVE-2026-129485"]
title: "Kroki: unauthenticated SSRF via BlockDiag diagrams reaches internal services"
severity: "medium"
cvss: 6.9
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "kroki", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["cloud-metadata", "kroki", "package", "self-hosted"]
not_affected_if: ["managed-hosting", "version-0.36.0-or-later"]
published_at: "2026-11-15T16:16:56+00:00"
first_seen_at: "2026-11-15T16:35:38+00:00"
updated_at: "2026-11-15T16:37:11+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-129485", "first_seen_at": "2026-11-15T16:35:38+00:00"}]
exploit_sources: []
---

# Kroki: unauthenticated SSRF via BlockDiag diagrams reaches internal services

Link for people: https://infrastack.ai/live/CVE-2026-129485 (this .md is for agents)

Kroki before 0.36.0 lets an unauthenticated attacker send a crafted BlockDiag diagram whose node icon or background attributes make the server issue requests. An attacker can use this to query internal services or cloud metadata and read local image files.

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

## Affected

- vendor:kroki affected range not listed fixed no fixed version listed

## How to check

- Check the running Kroki version: `kroki --version` or the image tag in your deployment, and see whether it is below `0.36.0`.
- Check whether the BlockDiag endpoints (`POST /blockdiag/svg` and sibling endpoints) are reachable from untrusted networks.

## Fix

- Kroki: move to `0.36.0` or later.

## Timeline

- 2026-11-15T16:35:38+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-129485

## Documents

- [advisory] Vendor advisory: github.com https://github.com/yuzutech/kroki/security/advisories/GHSA-jwh8-j584-79hp
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/kroki-before-0.36.0-ssrf-via-blockdiag-icon-and-background-attributes
- [fix] Patch: github.com https://github.com/yuzutech/kroki/commit/becd3b4a86754cb08d0fe54f65e92a6cab542409
- [fix] Release notes: github.com https://github.com/yuzutech/kroki/releases/tag/v0.36.0

## From the sources

Kroki before 0.36.0 contains a server-side request forgery vulnerability in the BlockDiag family of engines that allows unauthenticated attackers to make server requests via node icon and background attributes. Attackers can send crafted diagrams to POST /blockdiag/svg or sibling endpoints to query internal services or cloud metadata and read local image files from the server.

---

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