TI-2026-27527 Aliases CVE-2026-35391

Bulwark Webmail getClientIP() trusted client-controlled X-Forwarded-For value, enabling…

LOW 37CWE-348Published 2026-04-06 · Updated 2026-04-07

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: —
Confidentiality · integrity · availability: None · High · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00138 3rd percentileScored 2026-11-07

Fix Fixed webmail (bulwarkmail): 1.4.11

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
bulwarkmail	webmail	before 1.4.11	1.4.11	Patch available	CNA

webmail Vendorbulwarkmail Affected before 1.4.11 Fixed in 1.4.11 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:bulwarkmail:webmail::::::::	before 1.4.11	Vulnerable	bulwarkmail

cpe:2.3:a:bulwarkmail:webmail:*:*:*:*:*:*:*:* Versions before 1.4.11 Vulnerable ·bulwarkmail

Remediation

Fix · CNA webmail (bulwarkmail) Fixed in 1.4.11

Timeline

2026-10-02 Threatist record created from CVE-2026-35391

References

Advisory 1

https://github.com/bulwarkmail/webmail/security/advisories/GHSA-7pj2-232x-6698

TI-2026-27078 Bulwark Webmail: Authentication Bypass in verifyIdentity() due to missing cookie validation CVSS 4.0HIGH 8.7
TI-2026-27077 Bulwark Webmail: Information Exposure: password returned in /api/auth/session CVSS 4.0HIGH 8.7
TI-2026-27525 Bulwark Webmail S/MIME signature verification accepted self-signed certificates CVSS 4.0HIGH 8.7
TI-2026-27526 Content-Security-Policy was set to Report-Only mode, failing to block XSS attacks CVSS 4.0MEDIUM 5.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences