CVE-2026-50630 — cxf-rt-rs-security-oauth2
MEDIUMCVE-2026-50630 is a medium-severity (CVSS 6.5) CWE-113 vulnerability in org.apache.cxf:cxf-rt-rs-security-oauth2. A fix is available for org.apache.cxf:cxf-rt-rs-security-oauth2 — see the affected versions and patch details below.
Apache CXF: OAuth2: HTTP Response Splitting via WWW-Authenticate Realm Injection
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-50630.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-50630 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 382,621 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
org.apache.cxf:cxf-rt-rs-security-oauth2☕org.apache.cxf:cxf-rt-rs-security-oauth2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
A CRLF injection vulnerability exists in the OAuth2 AuthorizationUtils class. When constructing the WWW-Authenticate response header, the 'realm' parameter is concatenated without sanitizing Carriage Return (CR) and Line Feed (LF) characters. If an attacker can control the realm value, they can inject arbitrary HTTP headers or split the HTTP response entirely. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.cxf:cxf-rt-rs-security-oauth2 | ≥ 4.2.0&&< 4.2.2 | 4.2.2org.apache.cxf:cxf-rt-rs-security-oauth2:4.2.2 |
| ☕Maven | org.apache.cxf:cxf-rt-rs-security-oauth2 | all versions | 4.1.7org.apache.cxf:cxf-rt-rs-security-oauth2:4.1.7 |
Affected Products
cxfapacheDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.cxf:cxf-rt-rs-security-oauth2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.cxf:cxf-rt-rs-security-oauth2 to 4.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-50630 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-50630 in your dependencies?
Find it across Maven, including transitive dependencies.