CVE-2026-50631 — cxf-rt-rs-security-oauth2
HIGHCVE-2026-50631 is a high-severity (CVSS 7.4) CWE-367 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: TOCTOU Race Condition in Refresh Token Processing
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2026-50631.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-50631 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 383,485 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 race condition in AbstractOAuthDataProvider allows concurrent requests using the same Refresh Token to bypass single-use semantics and generate multiple valid Access Tokens, when 'recycleRefreshTokens' is set to false. A leaked refresh token can be replayed concurrently by multiple attackers or threads. 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-2026-50631 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-2026-50631 in your dependencies?
Find it across Maven, including transitive dependencies.