Medium severity4.3NVD Advisory· Published May 15, 2026· Updated May 18, 2026
CVE-2026-4054
CVE-2026-4054
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
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
github.com/mattermost/mattermost-serverGo | >= 11.5.0, < 11.5.2 | 11.5.2 |
github.com/mattermost/mattermost-serverGo | >= 0.0.0-20250731163400-5b955468ea1e, < 0.0.0-20260414103857-b21ef302025e | 0.0.0-20260414103857-b21ef302025e |
github.com/mattermost/mattermost-serverGo | >= 11.4.0, < 11.4.4 | 11.4.4 |
Affected products
2<=11.5.1,<=10.11.13,<=11.4.3+ 1 more
- (no CPE)range: <=11.5.1,<=10.11.13,<=11.4.3
- cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*range: >=10.11.0,<10.11.14
Patches
Vulnerability mechanics
References
3- github.com/advisories/GHSA-j76w-p754-g2w7ghsaADVISORY
- mattermost.com/security-updatesnvdVendor AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2026-4054ghsaADVISORY
News mentions
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