How severe is CVE-2026-35391?

CVE-2026-35391 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-35391 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-35391?

CVE-2026-35391 affects Bulwarkmail Webmail. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-35391?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-35391 have an EU (EUVD) identifier?

Yes. CVE-2026-35391 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19480.

When was CVE-2026-35391 published?

CVE-2026-35391 was published on 2026-04-06 and last updated on 2026-06-17.

CVE-2026-35391

CVE-2026-35391 is a high-severity vulnerability in Bulwarkmail Webmail with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-348.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-19480
Weakness: CWE-348
Affected product: Bulwarkmail Webmail
Published: 2026-04-06
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-35391?: 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.
How severe is CVE-2026-35391?: CVE-2026-35391 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-35391 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-35391?: CVE-2026-35391 affects Bulwarkmail Webmail. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-35391?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-35391 have an EU (EUVD) identifier?: Yes. CVE-2026-35391 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19480.
When was CVE-2026-35391 published?: CVE-2026-35391 was published on 2026-04-06 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:bulwarkmail:webmail:*:*:*:*:*:*:*:*

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