CVE-2026-35390 — Content-Security-Policy was set to Report-Only mode, failing to block XSS attacks
Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.4.11, the reverse proxy (proxy.ts) set the Content-Security-Policy-Report-Only header instea…
Published: 2026-04-06 · CVSS: 5.3 · CVSS 4.0
Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.4.11, the reverse proxy (proxy.ts) set the Content-Security-Policy-Report-Only header instead of the enforcing Content-Security-Policy header. This means cross-site scripting (XSS) attacks were logged but not blocked. Any user who could inject script content (e.g., via crafted email HTML) could execute arbitrary JavaScript in the context of the application, potentially stealing session tokens or performing actions on behalf of the user. This vulnerability is fixed in 1.4.11.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7