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GHSA-j76w-p754-g2w7
GHSA-j76w-p754-g2w7

Author: advisory-database[bot]

advisories/github-reviewed/2026/05/GHSA-j76w-p754-g2w7/GHSA-j76w-p754-g2w7.json

@@ -0,0 +1,99 @@
+{
+  "schema_version": "1.4.0",
+  "id": "GHSA-j76w-p754-g2w7",
+  "modified": "2026-05-28T19:28:48Z",
+  "published": "2026-05-15T21:31:33Z",
+  "aliases": [
+    "CVE-2026-4054"
+  ],
+  "summary": "Mattermost doesn't validate the response body of proxied images",
+  "details": "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.",
+  "severity": [
+    {
+      "type": "CVSS_V3",
+      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L"
+    }
+  ],
+  "affected": [
+    {
+      "package": {
+        "ecosystem": "Go",
+        "name": "github.com/mattermost/mattermost-server"
+      },
+      "ranges": [
+        {
+          "type": "ECOSYSTEM",
+          "events": [
+            {
+              "introduced": "11.5.0"
+            },
+            {
+              "fixed": "11.5.2"
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "package": {
+        "ecosystem": "Go",
+        "name": "github.com/mattermost/mattermost-server"
+      },
+      "ranges": [
+        {
+          "type": "ECOSYSTEM",
+          "events": [
+            {
+              "introduced": "0.0.0-20250731163400-5b955468ea1e"
+            },
+            {
+              "fixed": "0.0.0-20260414103857-b21ef302025e"
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "package": {
+        "ecosystem": "Go",
+        "name": "github.com/mattermost/mattermost-server"
+      },
+      "ranges": [
+        {
+          "type": "ECOSYSTEM",
+          "events": [
+            {
+              "introduced": "11.4.0"
+            },
+            {
+              "fixed": "11.4.4"
+            }
+          ]
+        }
+      ]
+    }
+  ],
+  "references": [
+    {
+      "type": "ADVISORY",
+      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4054"
+    },
+    {
+      "type": "PACKAGE",
+      "url": "https://github.com/mattermost/mattermost"
+    },
+    {
+      "type": "WEB",
+      "url": "https://mattermost.com/security-updates"
+    }
+  ],
+  "database_specific": {
+    "cwe_ids": [
+      "CWE-754"
+    ],
+    "severity": "MODERATE",
+    "github_reviewed": true,
+    "github_reviewed_at": "2026-05-28T19:28:48Z",
+    "nvd_published_at": "2026-05-15T19:17:04Z"
+  }
+}