MEDIUM
Opening a window with {{javascript:alert()}} as URL causes crash in the Mattermost Desktop App
Published May 18, 2026
6.5
MEDIUMCVSS 3.1
EPSS 0.33%
Description
Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent an invalid URL from loading in a pop-up window in the Mattermost Desktop App which allows a malicious server owner to repeated crash the application via calling {{window.open('javascript:alert()');}}. Mattermost Advisory ID: MMSA-2026-00618
Affected products
-
- Version 0StatusaffectedConstraints<=5.4.13
- Version 0StatusaffectedConstraints<=6.0.1
- Version 5.13.5.0StatusunaffectedConstraints-
- Version 6.1.1.0StatusunaffectedConstraints-
- Version 6.2.0StatusunaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mattermost | Mattermost | unaffected |
|
OR
- ≤ 5.4.13.0
- ≥ 6.0.0 · ≤ 6.0.1
- ≥ 6.1.0 · < 6.2.0
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
Vendor solution
Update Mattermost Desktop App to versions 6.2.0, 6.1.1.0, 5.13.5.0 or higher.
Weaknesses (1)
References (2)
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-30757 Advisory
- https://mattermost.com/security-updates vendor-advisoryVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-30757 | Advisory | |
| https://mattermost.com/security-updates | vendor-advisoryVendor Advisory |
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner Mattermost
Published May 18, 2026
Updated May 18, 2026
Reserved Mar 3, 2026
Link CVE-2026-3471
CISA Vulnrichment
Updated May 18, 2026
ENISA EUVD
EUVD-2026-30757 Assigner Mattermost
Published May 18, 2026
Updated May 18, 2026
Exploited since n/a
Link EUVD-2026-30757