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Vulnerability record · CVE-2026-35391 · published 6 April 2026

CVE-2026-35391: Bulwarkmail webmail vulnerability

Bulwarkmail · Webmail

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.

8.7 CVSS 4.0 High EPSS 0.19% · top 91.8% CWE-348 · CWE-348
8.7CVSS 4.0 base score
0.19%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References
24 Jul 2026Last modified by NVD

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.

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.7CVE-2026-35389Bulwarkmail webmail improper certificate validation vulnerabilityBulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.4.11, S/MIME signature verification did not validate the certifi…EPSS 0.24%8.7CVE-2026-34833Bulwarkmail webmail cleartext storage of sensitive data vulnerabilityBulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to version 1.4.10, the GET /api/auth/session endpoint previously incl…EPSS 0.27%8.7CVE-2026-34834Bulwarkmail webmail improper authentication vulnerabilityBulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to version 1.4.10, the verifyIdentity() function contained logic that…EPSS 0.42%5.3CVE-2026-35390Bulwarkmail webmail cross-site scripting vulnerabilityBulwark 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-Poli…EPSS 0.23%

Source: NIST National Vulnerability Database (record CVE-2026-35391), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.