CVE-2026-50631: A race condition in AbstractOAuthDataProvider allows concurrent requests using the same Refresh Token to bypas

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HIGH 7.4REMOTEWATCHLISTUPGRADE

CVE-2026-50631 is a high-severity flaw (CVSS 7.4) affecting cxf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.4 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 78%)
CISA exploited list	No
Weakness	CWE-367
Published	2026-06-12
Last modified	2026-10-26

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-12 10:16 UTCPublished CVE record published
2026-10-26 11:10 UTCUpdated Record last modified

apache cxf UPGRADE

Affected: < 4.1.7 · >= 4.2.0 and < 4.2.2

Fixed in: 4.1.7, 4.2.2

Safe to downgrade to: a release before 4.2.0

1. Check installed version

apt-cache policy cxf || rpm -q cxf || cxf --version

2. UPGRADE to 4.1.7 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade cxf

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade cxf

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 4.2.0 (Debian / Ubuntu)

apt-cache madison cxf sudo apt install cxf=<VERSION_BEFORE_4.2.0> sudo apt-mark hold cxf

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list cxf sudo dnf downgrade cxf-<VERSION_BEFORE_4.2.0> sudo dnf versionlock add cxf

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-50631?

cxf: upgrade to 4.1.7, 4.2.2. Exact commands for each OS are on this page.

Is CVE-2026-50631 being exploited?

CVE-2026-50631 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-50631 affect?

CVE-2026-50631 affects cxf. Severity is high (CVSS 7.4). 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 to

How urgent is CVE-2026-50631?

Priority 41/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Related CVEs

CVE-2026-50628 CRITICAL 9.8 UPGRADE A logic error in OAuthRequestFilter rejects legitimate requests originating from the bound IP address, while b
CVE-2026-50627 CRITICAL 9.1 UPGRADE The JwtAccessTokenValidator class in Apache CXF fails to validate the 'aud' (Audience) claims of incoming JWT
CVE-2026-49875 CRITICAL 9.8 UPGRADE Apache CXF's EndpointReferenceUtils and W3CMultiSchemaFactory classes construct a SAXParserFactory without the
CVE-2026-50633 HIGH 8.1 UPGRADE A JNDI Injection vulnerability has been discovered in Apache CXF's JCA integration module, which can allow for
CVE-2026-50632 HIGH 8.1 UPGRADE A further incomplete fix for a previous advisory CVE-2026-44417 (Untrusted JMS configuration can lead to RCE)

References

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