CVE-2021-20262: A flaw was found in Keycloak 12.0.0 where re-authentication does not occur while updating the password

Routine

MEDIUM 6.8WATCHLISTDOWNGRADEDOWNGRADE

CVE-2021-20262 is a medium-severity flaw (CVSS 6.8) 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 12.0.0 where re-authentication does not occur while updating the password. This flaw allows an attacker to take over an account if they can obtain temporary, physical access to a user’s browser. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

Why this priority

On your watchlist

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

Risk facts

CVSS score	6.8 (Medium)
Attack vector	Physical
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-306
Published	2021-03-09
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

2021-03-09 18:15 UTCPublished CVE record published
2026-06-17 03:33 UTCUpdated Record last modified

redhat keycloak DOWNGRADE

Affected: 12.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 12.0.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 12.0.0 (Debian / Ubuntu)

apt-cache madison keycloak sudo apt install keycloak=<VERSION_BEFORE_12.0.0> sudo apt-mark hold keycloak

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

dnf --showduplicates list keycloak sudo dnf downgrade keycloak-<VERSION_BEFORE_12.0.0> sudo dnf versionlock add keycloak

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.

redhat single sign-on DOWNGRADE

Affected: 7.0

Fixed in: no fixed release known

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. No fixed release: 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

2. No fixed release: 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-2021-20262?

keycloak: downgrade 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-2021-20262 being exploited?

CVE-2021-20262 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-2021-20262 affect?

CVE-2021-20262 affects keycloak, single sign-on. Severity is medium (CVSS 6.8). A flaw was found in Keycloak 12.0.0 where re-authentication does not occur while updating the password. This flaw allows an attacker to take over an account if they can obtain temporary, physical access to a user’s browser. The highest thre

How urgent is CVE-2021-20262?

Priority 35/100. 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

← Back to latest CVEs