CVE-2021-3632: A flaw was found in Keycloak

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HIGH 7.5WATCHLISTUPGRADEUPGRADE

CVE-2021-3632 is a high-severity flaw (CVSS 7.5) affecting keycloak, single sign-on. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw was found in Keycloak. This vulnerability allows anyone to register a new security device or key when there is not a device already registered for any user by using the WebAuthn password-less login flow.

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.2% (top 33%)
CISA exploited list	No
Weakness	CWE-287
Published	2022-08-26
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

2022-08-26 16:15 UTCPublished CVE record published
2026-06-17 04:05 UTCUpdated Record last modified

redhat keycloak UPGRADE

Affected: < 15.1.0

Fixed in: 15.1.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 15.1.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade keycloak

Note

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

redhat single sign-on UPGRADE

Affected: 7.0 · >= 7.4 and < 7.4.9

Fixed in: 7.4.9

Safe to downgrade to: a release before 7.0

1. Check installed version

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

2. UPGRADE to 7.4.9 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade single-sign-on

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade single-sign-on

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 7.0 (Debian / Ubuntu)

apt-cache madison single-sign-on sudo apt install single-sign-on=<VERSION_BEFORE_7.0> sudo apt-mark hold single-sign-on

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

dnf --showduplicates list single-sign-on sudo dnf downgrade single-sign-on-<VERSION_BEFORE_7.0> 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-2021-3632?

keycloak: upgrade to 15.1.0; single sign-on: upgrade to 7.4.9. Exact commands for each OS are on this page.

Is CVE-2021-3632 being exploited?

CVE-2021-3632 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-2021-3632 affect?

CVE-2021-3632 affects keycloak, single sign-on. Severity is high (CVSS 7.5). A flaw was found in Keycloak. This vulnerability allows anyone to register a new security device or key when there is not a device already registered for any user by using the WebAuthn password-less login flow.

How urgent is CVE-2021-3632?

Priority 48/100. 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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