Kroki creates diagrams from textual descriptions. From 0.26.0 until 0.31.2, the optional Mermaid companion's mermaid/src/worker.js renders attacker-controlled flowchart image nodes in headless Chromium without a network request policy, even when KROKI_SAFE_MODE is set to secure. An actor who can submit Mermaid source and satisfy any authentication or authorization configured by the deployment can cause the companion to issue HTTP or HTTPS GET requests when requesting PNG output. Exploitation requires the Mermaid companion, PNG rendering through its headless Chromium process, a diagram-submission path available to the actor, and network reachability from the companion to the target. The demonstrated impact is limited to blind request reachability and possible state-changing GET endpoints; response exfiltration, cloud metadata access, port scanning, and access beyond the companion's network reachability are not established. This issue is fixed in version 0.31.2.

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History

Fri, 06 Nov 2026 17:45:00 +0000

Type Values Removed Values Added
Description Kroki creates diagrams from textual descriptions. From 0.26.0 until 0.31.2, the optional Mermaid companion's mermaid/src/worker.js renders attacker-controlled flowchart image nodes in headless Chromium without a network request policy, even when KROKI_SAFE_MODE is set to secure. An actor who can submit Mermaid source and satisfy any authentication or authorization configured by the deployment can cause the companion to issue HTTP or HTTPS GET requests when requesting PNG output. Exploitation requires the Mermaid companion, PNG rendering through its headless Chromium process, a diagram-submission path available to the actor, and network reachability from the companion to the target. The demonstrated impact is limited to blind request reachability and possible state-changing GET endpoints; response exfiltration, cloud metadata access, port scanning, and access beyond the companion's network reachability are not established. This issue is fixed in version 0.31.2.
Title Kroki Mermaid companion SSRF via flowchart image URLs
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-11-06T17:38:49.280Z

Reserved: 2026-09-28T22:38:42.255Z

Link: CVE-2026-102356

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-06T18:17:36.717

Modified: 2026-11-06T18:17:36.717

Link: CVE-2026-102356

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-06T19:00:12Z

Weaknesses