Is CVE-2026-1628 in the CISA KEV catalog?

No. CVE-2026-1628 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-1628?

CVE-2026-1628 has a CVSS v3 base score of 4.6 (MEDIUM).

What is the EPSS score for CVE-2026-1628?

CVE-2026-1628 has an EPSS score of 0.14% (3th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-1628?

Upgrade Mattermost to 5.13.4 or later.

CVE & CISA-KEV Catalog

CVE-2026-1628

MEDIUM

4.6

CVSS v3

NVD

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

CWE-829

How to fix

Remediation Available

MattermostWindows application

Affected:5.13.4Fixed in:5.13.4Mattermost, Inc.

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 RequiredLow

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

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

mattermost.com

Related Vulnerabilities

Other CWE-829 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2018-17246	Critical	9.8	82%	-	Fix
CVE-2024-5762	High	8.1	72%	-	-
CVE-2018-7422	High	7.5	63%	-	-
CVE-2023-2249	High	8.8	61%	-	-
CVE-2025-32463	Critical	9.3	47%	KEV	Fix
CVE-2024-38476	Critical	9.8	42%	-	Fix

Embed a live status badge for CVE-2026-1628

Markdown

[![CVE-2026-1628](https://tridentstack.com/cve/badge/CVE-2026-1628.svg)](https://tridentstack.com/cve/CVE-2026-1628)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-1628"><img src="https://tridentstack.com/cve/badge/CVE-2026-1628.svg" alt="CVE-2026-1628"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

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 2026-03-05.