CVE-2026-4054

4.3 MEDIUM

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to validate the response body of proxied images, which a...

Published: 2026-05-15 · Last updated: 2026-05-18

Severity and scoring

CVSS: 4.3 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
CWE: CWE-754

Affected products

Vendor	Product
mattermost	mattermost_server

Description

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to validate the response body of proxied images, which allows a remote attacker to enact client-side DoS via an SVG file served from an attacker-controlled origin under a non-SVG Content-Type header (e.g. image/png) embedded in an og:image meta tag or Markdown image link.. Mattermost Advisory ID: MMSA-2026-00630

Source: NVD

References

[NVD]https://nvd.nist.gov/vuln/detail/CVE-2026-4054
[Vendor advisory]https://mattermost.com/security-updates

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