In deployments of WSO2 Identity Server configured with a case-insensitive user store and a…
CVE-2026-6647 is a high-severity vulnerability in WSO2 Identity Server from WSO2, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 7.2.0.21 as the first without the flaw, so updating WSO2 Identity Server to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update WSO2 Identity Server to 7.2.0.21 or a later version.
- Update WSO2 Carbon OAuth to 7.0.385.17 or a later version.
- Read the advisory on security.docs.wso2.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| WSO2 | WSO2 Identity Server | 7.2.0 up to, but not including, 7.2.0.21 | 7.2.0.21 |
| WSO2 | WSO2 Carbon OAuth | 7.0.385 up to, but not including, 7.0.385.17 | 7.0.385.17 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L. Scored by CNA.
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in WSO2 Identity Server
- 7.2 High severity
- 8.3 High severity
- 7.4 High severity
- 8.2 High severity
- 9.1 Critical severity
- 8.4 High severity
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