CVE-2026-110008

Full vulnerability record from the local CVENow database.

Description

@fastify/oauth2 is a Fastify wrapper for OAuth2 login flows. In versions 7.2.0 through 8.3.1, the state and code-verifier cookies are set without a Path attribute at a login route with two or more path segments, while the clearing step at the OAuth callback writes them with a root path, so the original cookies survive the callback and the documented single-use guarantee for the state value does not hold. A state value an attacker learns stays valid for the rest of the browser session, letting the attacker drive their own authorization flow in the victim's browser and sign the victim in to the attacker's account (login CSRF). The issue is fixed in @fastify/oauth2 8.3.2, and users should upgrade to 8.3.2 or later. As a workaround, set an explicit cookie path so the set and the clear name the same cookie.

Severity

MEDIUM

CVSS score

4.2 (v3.1)

Vulnerability status

Awaiting Analysis

Source identifier

ce714d77-add3-4f53-aff5-83d477b104bb

Published

2026-10-19 14:16:57.527000

Last modified

2026-10-19 21:13:39.973000

View original CVE JSON

{
  "id": "CVE-2026-110008",
  "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb",
  "published": "2026-10-19T14:16:57.527",
  "lastModified": "2026-10-19T21:13:39.973",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "@fastify/oauth2 is a Fastify wrapper for OAuth2 login flows. In versions 7.2.0 through 8.3.1, the state and code-verifier cookies are set without a Path attribute at a login route with two or more path segments, while the clearing step at the OAuth callback writes them with a root path, so the original cookies survive the callback and the documented single-use guarantee for the state value does not hold. A state value an attacker learns stays valid for the rest of the browser session, letting the attacker drive their own authorization flow in the victim's browser and sign the victim in to the attacker's account (login CSRF). The issue is fixed in @fastify/oauth2 8.3.2, and users should upgrade to 8.3.2 or later. As a workaround, set an explicit cookie path so the set and the clear name the same cookie."
    }
  ],
  "affected": [
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "affectedData": [
        {
          "vendor": "@fastify/oauth2",
          "product": "@fastify/oauth2",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/@fastify/oauth2",
          "versions": [
            {
              "version": "7.2.0",
              "lessThan": "8.3.2",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "8.3.2",
              "versionType": "semver",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N",
          "baseScore": 4.2,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 2.5
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-19T14:26:36.141774Z",
          "id": "CVE-2026-110008",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-352"
        },
        {
          "lang": "en",
          "value": "CWE-459"
        },
        {
          "lang": "en",
          "value": "CWE-613"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://cna.openjsf.org/security-advisories.html",
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb"
    },
    {
      "url": "https://github.com/fastify/fastify-oauth2/security/advisories/GHSA-7fcr-mwg4-pw9q",
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb"
    }
  ]
}