Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, a user full name can be evaluated as raw HTML when the following settings are set: display_name_on_posts => true; and prioritize_username_in_ux => false. Editing a post of a malicious user would trigger an XSS. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27154.json",
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-79"
]
}{
"versions": [
{
"introduced": "0"
},
{
"fixed": "2025.12.2"
}
]
}