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GHSA-95H4-W6J8-2RP8

Vulnerability from github – Published: 2025-09-02 15:31 – Updated: 2026-06-30 03:35
VLAI
Summary
Undertow MadeYouReset HTTP/2 DDoS Vulnerability
Details

A flaw was found in Undertow where malformed client requests can trigger server-side stream resets without triggering abuse counters. This issue, referred to as the "MadeYouReset" attack, allows malicious clients to induce excessive server workload by repeatedly causing server-side stream aborts. While not a protocol bug, this highlights a common implementation weakness that can be exploited to cause a denial of service (DoS).

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "io.undertow:undertow-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.2.38.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "io.undertow:undertow-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.3.0.Alpha1"
            },
            {
              "fixed": "2.3.20.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-9784"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-404",
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-09-02T20:54:27Z",
    "nvd_published_at": "2025-09-02T14:15:36Z",
    "severity": "HIGH"
  },
  "details": "A flaw was found in Undertow where malformed client requests can trigger server-side stream resets without triggering abuse counters. This issue, referred to as the \"MadeYouReset\" attack, allows malicious clients to induce excessive server workload by repeatedly causing server-side stream aborts. While not a protocol bug, this highlights a common implementation weakness that can be exploited to cause a denial of service (DoS).",
  "id": "GHSA-95h4-w6j8-2rp8",
  "modified": "2026-06-30T03:35:21Z",
  "published": "2025-09-02T15:31:08Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-9784"
    },
    {
      "type": "WEB",
      "url": "https://github.com/undertow-io/undertow/pull/1805"
    },
    {
      "type": "WEB",
      "url": "https://github.com/undertow-io/undertow/pull/1804"
    },
    {
      "type": "WEB",
      "url": "https://github.com/undertow-io/undertow/pull/1803"
    },
    {
      "type": "WEB",
      "url": "https://github.com/undertow-io/undertow/pull/1802"
    },
    {
      "type": "WEB",
      "url": "https://github.com/undertow-io/undertow/pull/1778"
    },
    {
      "type": "WEB",
      "url": "https://www.kb.cert.org/vuls/id/767506"
    },
    {
      "type": "WEB",
      "url": "https://kb.cert.org/vuls/id/767506"
    },
    {
      "type": "WEB",
      "url": "https://issues.redhat.com/browse/UNDERTOW-2598"
    },
    {
      "type": "WEB",
      "url": "https://github.com/undertow-io/undertow/releases/tag/2.2.38.Final"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/undertow-io/undertow"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2392306"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2025-9784"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:4924"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:4917"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:4916"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:4915"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:3892"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:3891"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:3889"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:33372"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:33371"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:0386"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:0384"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:0383"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2025:23143"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Undertow MadeYouReset HTTP/2 DDoS Vulnerability"
}



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