GHSA-95H4-W6J8-2RP8

Vulnerability from github – Published: 2025-09-02 15:31 – Updated: 2026-01-09 00:30
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
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{
  "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": "2026-01-09T00:30:27Z",
  "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/1778"
    },
    {
      "type": "WEB",
      "url": "https://github.com/undertow-io/undertow/pull/1802"
    },
    {
      "type": "WEB",
      "url": "https://github.com/undertow-io/undertow/pull/1803"
    },
    {
      "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-2026:0386"
    },
    {
      "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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Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.