How severe is CVE-2026-35389?

CVE-2026-35389 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-2026-35389 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-35389?

CVE-2026-35389 affects Bulwarkmail Webmail. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-35389?

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-2026-35389 have an EU (EUVD) identifier?

Yes. CVE-2026-35389 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19478.

When was CVE-2026-35389 published?

CVE-2026-35389 was published on 2026-04-06 and last updated on 2026-06-17.

CVE-2026-35389

CVE-2026-35389 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-295.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-19478
Weakness: CWE-295
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, S/MIME signature verification did not validate the certificate trust chain (checkChain: false). Any email signed with a self-signed or untrusted certificate was displayed as having a valid signature. This vulnerability is fixed in 1.4.11.

Frequently asked questions

What is CVE-2026-35389?: Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.4.11, S/MIME signature verification did not validate the certificate trust chain (checkChain: false). Any email signed with a self-signed or untrusted certificate was displayed as having a valid signature. This vulnerability is fixed in 1.4.11.
How severe is CVE-2026-35389?: CVE-2026-35389 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-2026-35389 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-35389?: CVE-2026-35389 affects Bulwarkmail Webmail. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-35389?: 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-2026-35389 have an EU (EUVD) identifier?: Yes. CVE-2026-35389 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19478.
When was CVE-2026-35389 published?: CVE-2026-35389 was published on 2026-04-06 and last updated on 2026-06-17.

References

https://github.com/bulwarkmail/webmail/security/advisories/GHSA-v6w6-338p-p256

Affected products (1)

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

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