CVE-2026-6647

Full vulnerability record from the local CVENow database.

Description

In deployments of WSO2 Identity Server configured with a case-insensitive user store and a case-sensitive database for identity data, mismatches in username case handling can occur. This inconsistency results in OAuth token revocation operations failing to correctly identify usernames containing mixed-case characters during certain lifecycle events, preventing tokens from being invalidated. A malicious actor can exploit this vulnerability by possessing a valid access or refresh token associated with a mixed-case username. In affected configurations, these tokens may not be revoked when expected. The actor can then leverage these unrevoked tokens, before their expiry, to continue performing actions that should have been restricted, effectively bypassing intended access controls.

Severity

HIGH

CVSS score

7.4 (v3.1)

Vulnerability status

Awaiting Analysis

Source identifier

ed10eef1-636d-4fbe-9993-6890dfa878f8

Published

2026-10-28 20:18:44.080000

Last modified

2026-10-29 16:08:42.827000

View original CVE JSON

{
  "id": "CVE-2026-6647",
  "sourceIdentifier": "ed10eef1-636d-4fbe-9993-6890dfa878f8",
  "published": "2026-10-28T20:18:44.080",
  "lastModified": "2026-10-29T16:08:42.827",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In deployments of WSO2 Identity Server configured with a case-insensitive user store and a case-sensitive database for identity data, mismatches in username case handling can occur. This inconsistency results in OAuth token revocation operations failing to correctly identify usernames containing mixed-case characters during certain lifecycle events, preventing tokens from being invalidated.\n\nA malicious actor can exploit this vulnerability by possessing a valid access or refresh token associated with a mixed-case username. In affected configurations, these tokens may not be revoked when expected. The actor can then leverage these unrevoked tokens, before their expiry, to continue performing actions that should have been restricted, effectively bypassing intended access controls."
    }
  ],
  "affected": [
    {
      "source": "ed10eef1-636d-4fbe-9993-6890dfa878f8",
      "affectedData": [
        {
          "vendor": "WSO2",
          "product": "WSO2 Identity Server",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "7.2.0",
              "lessThan": "7.2.0.21",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "WSO2",
          "product": "WSO2 Carbon OAuth",
          "defaultStatus": "unknown",
          "packageName": "org.wso2.carbon.identity.inbound.auth.oauth2:org.wso2.carbon.identity.oauth",
          "versions": [
            {
              "version": "7.0.385",
              "lessThan": "7.0.385.17",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "7.5.23",
              "lessThanOrEqual": "*",
              "versionType": "custom",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "ed10eef1-636d-4fbe-9993-6890dfa878f8",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L",
          "baseScore": 7.4,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 3.1,
        "impactScore": 3.7
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-29T01:51:34.435159Z",
          "id": "CVE-2026-6647",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "ed10eef1-636d-4fbe-9993-6890dfa878f8",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-613"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5387/",
      "source": "ed10eef1-636d-4fbe-9993-6890dfa878f8"
    }
  ]
}