EUVD-2026-17552Severity by source
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Primary rating from Vendor (GitHub_M) · only source for this CVE.
CVSS VectorVendor: GitHub_M
Lifecycle Timeline
4DescriptionCVE.org
Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, when the hidden prioritize_full_name_in_ux site setting is enabled (defaults to false, requires console access to change), user and group display names are rendered without HTML escaping in several assignment-related UI paths. This allows users with assign permission to inject arbitrary HTML/JavaScript that executes in the browser of any user viewing an affected topic. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.
AnalysisAI
Stored cross-site scripting (XSS) in Discourse assignment UI allows authenticated users with assign permission to inject arbitrary HTML/JavaScript into user and group display names when the hidden prioritize_full_name_in_ux site setting is enabled, affecting versions 2026.1.0–2026.1.2, 2026.2.0–2026.2.1, and 2026.3.0. The injected payload executes in the browser of any user viewing an affected topic, enabling session hijacking, credential theft, or malware distribution. No active exploitation confirmed; however, the requirement for console access to enable the vulnerable setting and assign permission to exploit limits real-world impact, though the low CVSS score (2.1) reflects these constraints rather than severity of XSS itself.
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Same weakness CWE-79 – Cross-site Scripting (XSS)
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External POC / Exploit Code
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