Cyber Resilience

CVE-2026-50631

Race Condition in Apache Cxf ≤ 4.1.7

Race Condition
Published
12 June 2026
Modified
07 August 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0029 22th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-50631 is a high-severity Time-of-check Time-of-use (TOCTOU) Race Condition (CWE-367) vulnerability in Apache Cxf. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked at the 22th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-25 (Reference Monitor) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

or threads. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

CWE(s)
CWE-367

Related Threats

MITRE ATT&CK Enterprise Techniques

T1034 Path Interception Persistence
**This technique has been deprecated.
attack.mitre.org →
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
attack.mitre.org →
T1574 Hijack Execution Flow Stealth
Adversaries may execute their own malicious payloads by hijacking the way operating systems run programs.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-57818Same product: Apache Cxf
CVE-2026-44417Same product: Apache Cxf
CVE-2026-50623Same product: Apache Cxf
CVE-2026-68079Same product: Apache Cxf
CVE-2026-66909Same product: Apache Cxf
CVE-2024-41172Same product: Apache Cxf
CVE-2025-48795Same product: Apache Cxf
CVE-2024-29736Same product: Apache Cxf
CVE-2026-54225Same product: Apache Cxf
CVE-2026-57817Same product: Apache Cxf

Affected Assets

apache
cxf
≤ 4.1.7 · 4.2.0 — 4.2.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V15.4.2
  • V17.2.6

Mitigating Controls (NIST 800-53 r5) AI

AC-25 Reference Monitor good match

A reference monitor that is always invoked and analyzable structurally eliminates the non-atomic check-then-use pattern underlying TOCTOU.

AC-3 Access Enforcement partial match

Access enforcement that performs an atomic check-and-use decision directly stops the window in which a TOCTOU race can be exploited.

SC-39 Process Isolation partial match

Process isolation limits the blast radius of a successful TOCTOU exploitation but does not remove the race itself.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly include coding standards and reviews that prevent TOCTOU race conditions.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.17 Clock synchronization none match
none

Reliable, synchronized time across systems narrows the exploitable window in which a resource state can change between a security check and its use.

References