CVE-2022-4137: A reflected cross-site scripting (XSS) vulnerability was found in the 'oob' OAuth endpoint due to incorrect nu

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HIGH 8.1WATCHLISTMITIGATEDOWNGRADE

CVE-2022-4137 is a high-severity flaw (CVSS 8.1) affecting keycloak, single sign-on. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A reflected cross-site scripting (XSS) vulnerability was found in the 'oob' OAuth endpoint due to incorrect null-byte handling. This issue allows a malicious link to insert an arbitrary URI into a Keycloak error page. This flaw requires a user or administrator to interact with a link in order to be vulnerable. This may compromise user details, allowing it to be changed or collected by an attacker.

Why this priority

High severity
On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.2% (top 32%)
CISA exploited list	No
Weakness	CWE-81, CWE-79
Published	2023-09-25
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: redhat

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-09-25 20:15 UTCPublished CVE record published
2026-06-17 05:20 UTCUpdated Record last modified

redhat keycloak MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

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

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

redhat single sign-on DOWNGRADE

Affected: 7.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.6

1. Check installed version

apt-cache policy single-sign-on || rpm -q single-sign-on || single-sign-on --version

2. No fixed release: DOWNGRADE to a release before 7.6 (Debian / Ubuntu)

apt-cache madison single-sign-on sudo apt install single-sign-on=<VERSION_BEFORE_7.6> sudo apt-mark hold single-sign-on

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list single-sign-on sudo dnf downgrade single-sign-on-<VERSION_BEFORE_7.6> sudo dnf versionlock add single-sign-on

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-2022-4137?

keycloak: mitigate or apply the listed mitigation; single sign-on: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2022-4137 being exploited?

CVE-2022-4137 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-2022-4137 affect?

CVE-2022-4137 affects keycloak, single sign-on. Severity is high (CVSS 8.1). A reflected cross-site scripting (XSS) vulnerability was found in the 'oob' OAuth endpoint due to incorrect null-byte handling. This issue allows a malicious link to insert an arbitrary URI into a Keycloak error page. This flaw requires a u

How urgent is CVE-2022-4137?

Priority 50/100. High severity; On your watchlist

Software pages

Keycloak vulnerabilities

Related CVEs

CVE-2023-6927 MEDIUM 4.6 MITIGATE DOWNGRADE A flaw was found in Keycloak
CVE-2023-6563 HIGH 7.7 UPGRADE DOWNGRADE An unconstrained memory consumption vulnerability was discovered in Keycloak
CVE-2023-6291 HIGH 7.1 UPGRADE DOWNGRADE A flaw was found in the redirect_uri validation logic in Keycloak
CVE-2023-6134 MEDIUM 4.6 UPGRADE UPGRADE A flaw was found in Keycloak that prevents certain schemes in redirects, but permits them if a wildcard is app
CVE-2025-8419 MEDIUM 5.3 MITIGATE A vulnerability was found in Keycloak-services

References

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