CVE-2026-35390
MediumCVSS 5.4Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
Bulwark Webmail prior to version 1.4.11 sets the Content-Security-Policy-Report-Only header instead of the enforcing Content-Security-Policy header. This means XSS attacks are logged but not blocked, allowing arbitrary JavaScript execution via crafted email HTML.
Risk Assessment
An attacker can steal session tokens or perform actions on behalf of the user, leading to full email account takeover.
Recommendation
Update Bulwark Webmail to version 1.4.11 or later.
Other vulnerabilities in Bulwark Webmail
See all- CVE-2026-35391High
In Bulwark Webmail before 1.4.11, the getClientIP() function trusts the first (leftmost) entry of the X-Forwarded-For header, which is fully controlled by the client. An attacker can forge their source IP to bypass IP-based rate limiting (enabling brute-force attacks on the admin login) or forge audit log entries.
- CVE-2026-35389High
In Bulwark Webmail prior to 1.4.11, S/MIME signature verification did not validate the certificate trust chain, so any email signed with a self-signed or untrusted certificate was displayed as having a valid signature.
- CVE-2026-34834High
Bulwark Webmail before version 1.4.10 has a vulnerability in verifyIdentity() that returned true when no session cookies were present. This allows unauthenticated attackers to bypass security and access the /api/settings endpoint, modifying user settings.
- CVE-2026-34833High
Bulwark Webmail prior to version 1.4.10 exposed the user's plaintext password in the JSON response from the GET /api/auth/session endpoint. This exposed credentials to browser logs, local caches, and network proxies.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS