Is CVE-2026-35391 in the CISA KEV catalog?

No. CVE-2026-35391 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-35391?

CVE-2026-35391 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2026-35391?

CVE-2026-35391 has an EPSS score of 0.14% (3th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-35391?

Upgrade webmail to 1.4.11 or later.

CVE & CISA-KEV Catalog

CVE-2026-35391

HIGH

7.5

CVSS v3

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.

CWE-348

How to fix

Remediation Available

webmailNVD

Affected:< 1.4.11Fixed in:1.4.11CVE-2026-35391derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploit Intelligence

0.14%probability of exploitation in 30 days

3rdpercentile

Low risk: more likely to be exploited than 3% of all known CVEs.

References

Vendor Advisory1

github.com

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-09.