Apache CXF: Missing Critical Step in Authentication
CVE-2026-61466 is a critical-severity missing critical step in authentication vulnerability in Apache CXF from Apache, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 3.6.12, 4.1.8, 4.2.3 as the first without the flaw, so updating Apache CXF to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.71% chance of exploitation within 30 days, higher than 54% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Apache CXF to 3.6.12 or 4.1.8 or 4.2.3, whichever matches your release line, or a later version.
- Update Cxf to 3.6.12 or 4.1.8 or 4.2.3, whichever matches your release line, or a later version.
- Read the advisory on lists.apache.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache CXF | before 3.6.12; 4.0.0 up to, but not including, 4.1.8; 4.2.0 up to, but not including, 4.2.3 | 3.6.12, 4.1.8, 4.2.3 |
| Apache | Cxf | before 3.6.12; 4.0.0 up to, but not including, 4.1.8; 4.2.0 up to, but not including, 4.2.3 | 3.6.12, 4.1.8, 4.2.3 |
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
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H. Scored by CISA (ADP).
Official description
In Apache CXF's OAuth2 Dynamic Client Registration endpoint, the authorization server accepts and stores the `scope` value supplied in the client registration request verbatim, without validating it against an AS-defined allowlist. This could lead to a client self-assigning privileged scopes at registration time. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Critical Step in Authentication
The product implements an authentication technique, but it skips a step that weakens the technique.
More Missing Critical Step in Authentication vulnerabilities (CWE-304)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
Other vulnerabilities in Apache CXF
- 7.5 High severity
- 9.1 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
- 9.1 Critical severity
Recent Missing Critical Step in Authentication vulnerabilities
- 8.8 High severity
- 7.3 High severity
- 7.3 High severity
- 8.1 High severity
- 7.3 High severity
- 9.8 Critical severity
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