How severe is CVE-2026-1628?

CVE-2026-1628 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-1628 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-2026-1628?

CVE-2026-1628 affects Mattermost Mattermost Desktop. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-1628?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-1628 have an EU (EUVD) identifier?

Yes. CVE-2026-1628 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9174.

When was CVE-2026-1628 published?

CVE-2026-1628 was published on 2026-03-02 and last updated on 2026-06-17.

CVE-2026-1628

CVE-2026-1628 is a medium-severity vulnerability in Mattermost Mattermost Desktop with a CVSS 3.x base score of 4.6. 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-829.

Key facts

Severity: Medium (CVSS 3.x base score 4.6)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9174
Weakness: CWE-829
Affected product: Mattermost Mattermost Desktop
Published: 2026-03-02
Last modified: 2026-06-17

Description

Mattermost Desktop App versions <=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596

Frequently asked questions

What is CVE-2026-1628?: Mattermost Desktop App versions <=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596
How severe is CVE-2026-1628?: CVE-2026-1628 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-1628 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-2026-1628?: CVE-2026-1628 affects Mattermost Mattermost Desktop. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-1628?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-1628 have an EU (EUVD) identifier?: Yes. CVE-2026-1628 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9174.
When was CVE-2026-1628 published?: CVE-2026-1628 was published on 2026-03-02 and last updated on 2026-06-17.

References

https://mattermost.com/security-updates

Affected products (1)

cpe:2.3:a:mattermost:mattermost_desktop:*:*:*:*:*:*:*:*

More vulnerabilities in Mattermost Mattermost Desktop

CVE-2016-11064 — Critical (CVSS 9.8): An issue was discovered in Mattermost Desktop App before 3.4.0. Strings could be executed as code via injection.
CVE-2019-20856 — Critical (CVSS 9.8): An issue was discovered in Mattermost Desktop App before 4.3.0 on macOS. It allows dylib injection.
CVE-2019-20861 — High (CVSS 8.8): An issue was discovered in Mattermost Desktop App before 4.2.2. It allows attackers to execute arbitrary code via a…
CVE-2026-1046 — High (CVSS 7.6): Mattermost Desktop App versions <=6.0 6.2.0 5.2.13.0 fail to validate help links which allows a malicious Mattermost…
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