ZDF
Sign inSign up

Vulnerabilities

Vulnerability · 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…

Published Mar 2, 2026 · catalog updated Jun 17, 2026 · mattermost desktop

Last checked Oct 26, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-1628. EPSS is 0.14%. Act only if a listed version of mattermost desktop is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium4.6
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.14%
Remediation
Version ranges on file
Affected products
cpe mattermost/mattermost desktop · stated mattermost desktop

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

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe mattermost/mattermost desktopversion unspecified
  • stated mattermost desktop<= 5.13.3

How to fix CVE-2026-1628

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-1628. EPSS is 0.14%. Act only if a listed version of mattermost desktop is installed.

Which versions are affected?

Compare what you have installed with mattermost desktop <= 5.13.3. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-829: Inclusion of Functionality from Untrusted Control Sphere. EPSS 0.14%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 2, 2026 · NIST NVD

    Detected

    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

  2. Jun 17, 2026 · NIST NVD

    Updated

    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

Sources

  • CVE.orgVulnerability recordCVE-2026-1628

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-1628

    30-day exploitation probability 0.14%

    first.org
  • NIST NVDVulnerability recordCVE-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 Matter

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 26, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 23, 2026
  • CVE.orgOct 16, 2026
  • NIST NVDOct 15, 2026