CVE-2026-6647
Incomplete OAuth Token Revocation via Case Mismatch in WSO2 Identity Server Allows Continued Access After Lifecycle Events
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.
INFO
Published Date :
Oct. 28, 2026, 8:18 p.m.
Last Modified :
Oct. 28, 2026, 8:18 p.m.
Remotely Exploit :
Yes !
Source :
ed10eef1-636d-4fbe-9993-6890dfa878f8
Affected Products
The following products are affected by CVE-2026-6647
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | ed10eef1-636d-4fbe-9993-6890dfa878f8 | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Configure case sensitivity uniformly for user stores and databases.
- Test token revocation with mixed-case usernames.
- Apply vendor patches or updates if available.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-6647.
| URL | Resource |
|---|---|
| https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5387/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-6647 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-6647
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-6647 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-6647 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by ed10eef1-636d-4fbe-9993-6890dfa878f8
Oct. 28, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L Added CWE CWE-613 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/6xxx/CVE-2026-6647.json">CVE-2026-6647</a> Added Reference https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5387/