CVE-2026-35391 PUBLISHED

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

Assigner: GitHub_M
Reserved: 02.04.2026 Published: 06.04.2026 Updated: 07.04.2026

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.

Metrics

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
CVSS Score: 8.7

Product Status

Vendor bulwarkmail
Product webmail
Versions
  • Version < 1.4.11 is affected

References

Problem Types

  • CWE-348: Use of Less Trusted Source CWE