Vulnerability · Published Apr 6, 2026 · Assigned by GitHub_M

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

High 8.7

In plain English

A high-severity security flaw in webmail from bulwarkmail. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).

Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.1%top 96.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

VendorProductVersions
bulwarkmail webmail < 1.4.11

Weakness: CWE-348 · 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

References