CVE-2026-42150

# PoC Concept for CVE-2026-42150 # This demonstrates the lack of escaping in HTML output generation. import html def vulnerable_render(data): # Simulates the vulnerable behavior in wlc < 2.0.0 # Direct interpolation without escaping HTML entities return f"<div class='translation'>{data}</div>" def patched_render(data): # Simulates the patched behavior in wlc >= 2.0.0 return f"<div class='translation'>{html.escape(data)}</div>" # Malicious payload injected via Weblate API (e.g., in a translation string) payload = '<img src=x onerror=alert("CVE-2026-42150 XSS")>' print("--- Vulnerable Output ---") print(vulnerable_render(payload)) print("\n--- Patched Output ---") print(patched_render(payload))

{"cve": {"id": "CVE-2026-42150", "sourceIdentifier": "[email protected]", "published": "2026-05-08T04:16:18.920", "lastModified": "2026-05-08T16:08:15.570", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "wlc is a Weblate command-line client using Weblate's REST API. Prior to version 2.0.0, the HTML output format in wlc embeds API response data into HTML without escaping, allowing cross-site scripting when the output is rendered in a browser. This issue has been patched in version 2.0.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:L", "baseScore": 5.1, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.0, "impactScore": 3.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://github.com/WeblateOrg/wlc/commit/0f3e58f6d7457b05d48ef40f579a172c4c8b8469", "source": "[email protected]"}, {"url": "https://github.com/WeblateOrg/wlc/pull/1327", "source": "[email protected]"}, {"url": "https://github.com/WeblateOrg/wlc/releases/tag/2.0.0", "source": "[email protected]"}, {"url": "https://github.com/WeblateOrg/wlc/security/advisories/GHSA-gx2m-mcc2-r4p3", "source": "[email protected]"}]}}