CVE-2026-50631

Apache CXF: OAuth2: TOCTOU Race Condition in Refresh Token Processing

7.4 HighFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: None

Exploit likelihood

0.29%Up 0.3 points since Jun 12, 2026

What each source reports

CVE List Score used 7.4

Apache CXF: OAuth2: TOCTOU Race Condition in Refresh Token Processing

Record: CVE-2026-50631
CVSS 3.1: 7.4 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-367
Updated: 2026-11-02

EUVDEUVD-2026-36399 7.4

Record: EUVD-2026-36399
CVSS 3.1: 7.4 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-83r6-96m8-r52p 7.4

Apache CXF OAuth2 TOCTOU Race Condition in Refresh Token Processing

Record: GHSA-83r6-96m8-r52p
CVSS 3.1: 7.4 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-367
Updated: 2026-11-02

NVD 7.4

Record: CVE-2026-50631
CVSS 3.1: 7.4 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-367
Updated: 2026-11-05

OSV 7.4

Apache CXF: OAuth2: TOCTOU Race Condition in Refresh Token Processing

Record: CVE-2026-50631
CVSS 3.1: 7.4 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-367
Updated: 2026-11-07

OSVGHSA-83r6-96m8-r52p 7.4

Apache CXF OAuth2 TOCTOU Race Condition in Refresh Token Processing

Record: GHSA-83r6-96m8-r52p
CVSS 3.1: 7.4 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-367
Updated: 2026-11-02

OSVRHLW-2026-fd244c7ea4e4e9e4 4.8

Lightwell Security Advisory: cxf-rt-rs-security-oauth2 3.6.9.rhlw-00003

Red Hat Lightwell has released org.apache.cxf:cxf-rt-rs-security-oauth2 3.6.9.rhlw-00003 with backported fixes for CVE-2026-50623, CVE-2026-50627, CVE-2026-50628, CVE-2026-50629, CVE-2026-50630, CVE-2026-50631, CVE-2026-57818, CVE-2026-61466, CVE-2026-63687, CVE-2026-68079, and CVE-2026-68481.

CVE-2026-50623: Apache CXF: Authentication Bypass in OAuth2 TokenIntrospectionService

CVE-2026-50627: Apache CXF: OAuth2: Missing JWT Audience and Issuer Validation in Access Token Validator

CVE-2026-50628: Apache CXF: OAuth2: Inverted IP Binding Check Defeats Security Control

CVE-2026-50629: Apache CXF: OAuth2: Log Injection via Unsanitized Client Identifier

CVE-2026-50630: Apache CXF: OAuth2: HTTP Response Splitting via WWW-Authenticate Realm Injection

CVE-2026-50631: Apache CXF: OAuth2: TOCTOU Race Condition in Refresh Token Processing

CVE-2026-57818: Apache CXF: OAuth2 Authorization Code Replay via TOCTOU in JCacheCodeDataProvider

CVE-2026-61466: Apache CXF: OAuth2 Dynamic Client Registration Scope Self-Escalation

CVE-2026-63687: Apache CXF: JwtRequestCodeFilter silently overrides outer PKCE and nonce parameters

CVE-2026-68079: Apache CXF: DefaultEncryptingCodeDataProvider allows unlimited authorization code replay

CVE-2026-68481: Apache CXF: Revocation bypass in DefaultEncryptingOAuthDataProvider

This patched artifact is a drop-in replacement for org.apache.cxf:cxf-rt-rs-security-oauth2 3.6.9 from Maven Central.

Record: RHLW-2026-fd244c7ea4e4e9e4
CVSS 3.1: 4.8 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`org.apache.cxf:cxf-rt-rs-security-oauth2` Maven	4.2.0 up to 4.2.2	4.2.2
`org.apache.cxf:cxf-rt-rs-security-oauth2` Maven	before 4.1.7	4.1.7
`org.apache.cxf:cxf-rt-rs-security-oauth2` Maven	4.2.0 up to 4.2.2, plus listed versions 4.2.1	4.2.2
`org.apache.cxf:cxf-rt-rs-security-oauth2` Maven	before 4.1.7, plus listed versions 2.6.02.6.12.6.102.6.112.6.12 Show 45 moreShow less 2.6.132.6.142.6.152.6.162.6.172.6.22.6.32.6.42.6.52.6.62.6.72.6.82.6.92.7.02.7.12.7.102.7.112.7.122.7.132.7.142.7.152.7.162.7.172.7.182.7.22.7.32.7.42.7.52.7.62.7.72.7.82.7.93.0.03.0.0-milestone13.0.0-milestone23.0.13.0.103.0.113.0.123.0.133.0.143.0.153.0.163.0.23.0.3	4.1.7
`org.apache.cxf:cxf-rt-rs-security-oauth2` Red Hat Lightwell:Maven From an advisory covering 11 CVEs	before 3.6.9.rhlw-00003, plus listed versions 2.6.02.6.12.6.102.6.112.6.12 Show 45 moreShow less 2.6.132.6.142.6.152.6.162.6.172.6.22.6.32.6.42.6.52.6.62.6.72.6.82.6.92.7.02.7.12.7.102.7.112.7.122.7.132.7.142.7.152.7.162.7.172.7.182.7.22.7.32.7.42.7.52.7.62.7.72.7.82.7.93.0.03.0.0-milestone13.0.0-milestone23.0.13.0.103.0.113.0.123.0.133.0.143.0.153.0.163.0.23.0.3	3.6.9.rhlw-00003

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected
Nov 5, 2026	facts	NVD
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-50631 is a high vulnerability (CVSS 7.4) in Apache Cxf, published June 12, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.29%, the 21st percentile. Fixed in org.apache.cxf:cxf-rt-rs-security-oauth2 4.2.2.

References

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