CVE-2021-20195: A flaw was found in keycloak in versions before 13.0.0

Q: How do I fix CVE-2021-20195?

keycloak: upgrade to 12.0.3. Exact commands for each OS are on this page.

Q: Is CVE-2021-20195 being exploited?

CVE-2021-20195 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-20195 affect?

CVE-2021-20195 affects keycloak. Severity is critical (CVSS 9.6). A flaw was found in keycloak in versions before 13.0.0. A Self Stored XSS attack vector escalating to a complete account takeover is possible due to user-supplied data fields not being properly encoded and Javascript code being used to proc

Q: How urgent is CVE-2021-20195?

Priority 56/100. Critical severity; On your watchlist

This month

CRITICAL 9.6WATCHLISTUPGRADE

CVE-2021-20195 is a critical-severity flaw (CVSS 9.6) affecting keycloak. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw was found in keycloak in versions before 13.0.0. A Self Stored XSS attack vector escalating to a complete account takeover is possible due to user-supplied data fields not being properly encoded and Javascript code being used to process the data. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Why this priority

Critical severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.6 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.2% (top 31%)
CISA exploited list	No
Weakness	CWE-20, CWE-116
Published	2021-05-28
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

2021-05-28 11:15 UTCPublished CVE record published
2026-06-17 03:33 UTCUpdated Record last modified

redhat keycloak UPGRADE

Affected: < 12.0.3

Fixed in: 12.0.3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 12.0.3 (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.

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-2021-20195?

keycloak: upgrade to 12.0.3. Exact commands for each OS are on this page.

Is CVE-2021-20195 being exploited?

CVE-2021-20195 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-2021-20195 affect?

CVE-2021-20195 affects keycloak. Severity is critical (CVSS 9.6). A flaw was found in keycloak in versions before 13.0.0. A Self Stored XSS attack vector escalating to a complete account takeover is possible due to user-supplied data fields not being properly encoded and Javascript code being used to proc

How urgent is CVE-2021-20195?

Priority 56/100. Critical severity; On your watchlist

Software pages

Keycloak vulnerabilities

Related CVEs

CVE-2023-6927 MEDIUM 4.6 MITIGATE DOWNGRADE A flaw was found in Keycloak
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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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