CVE-2026-35390

MEDIUM

Content-Security-Policy was set to Report-Only mode, failing to block XSS attacks

Title source: cna
STIX 2.1

Description

Bulwark 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-Policy-Report-Only header instead of the enforcing Content-Security-Policy header. This means cross-site scripting (XSS) attacks were logged but not blocked. Any user who could inject script content (e.g., via crafted email HTML) could execute arbitrary JavaScript in the context of the application, potentially stealing session tokens or performing actions on behalf of the user. This vulnerability is fixed in 1.4.11.

References (1)

Core 1
Core References

Scores

CVSS v3 5.4
EPSS 0.0017
EPSS Percentile 6.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (1)
bulwarkmail/webmail < 1.4.11 (2 CPE variants)
Published Apr 06, 2026
Tracked Since Apr 07, 2026