# CVE-2026-20719: DoS via URL Previews Rendering Malicious SVGs

> CVE-2026-20719: DoS via URL Previews Rendering Malicious SVGs. CVSS 4.3 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-20719
Last updated: 2026-06-17T10:17:44Z

- Published: 2026-03-25 16:30 UTC · Updated: 2026-06-17 10:17 UTC · Assigner: Mattermost
- CVSS: 4.3 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- EPSS: 0.36%, 29th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-754

## Description

Mattermost versions 11.4.x \<= 11.4.0, 11.3.x \<= 11.3.1, 11.2.x \<= 11.2.3, 10.11.x \<= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595

## Affected vendors and products

- Mattermost: Mattermost

## Tracked companies

- [Mattermost](https://rewindex.com/company/mattermost.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-20719)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-20719)
- [https://mattermost.com/security-updates](https://mattermost.com/security-updates)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-20719 · Markdown: https://rewindex.com/cve/CVE-2026-20719.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-20719 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:44:10.009Z