Medium severity · published Jun 12, 2026
CVE-2026-50623
Apache CXF: Authentication Bypass in OAuth2 TokenIntrospectionService
4.8
CVSS
0.4%
EPSS
No
On KEV
Description
An authentication bypass vulnerability exists in the OAuth2 TokenIntrospectionService in Apache CXF. Due to a missing 'throw' keyword in the security context check, the introspection endpoint (/services/oauth2/introspect) can be accessed by any unauthenticated network attacker. However note that this is a safeguard only in the case that someone forgot to enable authentication on the service. Users are recommended to upgrade to version 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AC
Apache CXF · Apache Software Foundation
4.2.0 before 4.2.2; 4.0.0 before 4.1.7; before 3.6.12 · source: vendor
CX
Cxf · Apache
before 4.1.7; 4.2.0 before 4.2.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-50623
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-50623
Vendor Advisory
https://lists.apache.org/thread/ydzj8m5mqmjy13xgyj9mkk9hfff63qq7
Mailing List
http://www.openwall.com/lists/oss-security/2026/06/11/3
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