CVE-2026-35391 HIGH

CVE-2026-35391: Bulwark Webmail getClientIP() trusted client-controlled X-Forwarded-For value, enabling rate limit bypass and audit log forgery

Vendor Bulwarkmail
Product webmail
Weakness CWE-348
Published April 6, 2026
Last update April 7, 2026
View on NVD All CVEs

CVSS base score

8.7/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.4.11, the getClientIP() function in lib/admin/session.ts trusted the first (leftmost) entry of the X-Forwarded-For header, which is fully controlled by the client. An attacker could forge their source IP address to bypass IP-based rate limiting (enabling brute-force attacks against the admin login) or forge audit log entries (making malicious activity appear to originate from arbitrary IP addresses). This vulnerability is fixed in 1.4.11.

Key dates

02Disclosure timeline

April 6, 2026 CVE published
April 7, 2026 Record updated