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Build Of KeycloakApplication · Redhat

CVE-2026-9802

MEDIUM · 6.8 CVSS v3.1 Published 2026-05-28
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
75/100
Remediation priority · High
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A flaw was found in Keycloak. When revokeRefreshToken=true is enabled and persistent session storage is in use, a server restart can reset internal timing mechanisms. This allows a remote attacker, who has previously captured a user's refresh token, to replay that token even after it has been revoked. Successful exploitation grants the attacker unauthorized access to the victim's account, potentially leading to information disclosure or privilege escalation.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Keycloak suffers from a refresh token replay vulnerability when revokeRefreshToken=true is enabled with persistent session storage. Server restart resets internal timing mechanisms used to track token revocation, allowing an attacker with a previously captured refresh token to replay it after revocation and gain unauthorized access.

MitigationUpgrade to a patched Keycloak version or alternatively reduce refresh token validity periods and implement stricter token rotation. Review session storage configuration for potential timing-related issues.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Build Of KeycloakApplication
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate Keycloak configuration files
    Find the keycloak.conf or standalone.xml/standalone-ha.xml configuration file in your Keycloak installation directory. Common paths include $KEYCLOAK_HOME/conf/keycloak.conf or $JBOSS_HOME/standalone/configuration/standalone.xml.
    Affected if The configuration file cannot be located or Keycloak is not installed.
  2. Check if token revocation is enabled
    Search the configuration file for the setting 'revokeRefreshToken=true'. This parameter controls whether refresh tokens are invalidated after use.
    Affected if revokeRefreshToken is set to true in the configuration.
  3. Identify session storage configuration
    Examine the configuration for session storage settings. Look for persistent session storage indicators such as database (JDBC), infinispan cache with persistence, or distributed cache backends. Check for session datasources, cache container definitions with persistent cache stores, or database session tables.
    Affected if Persistent session storage (database-backed or distributed cache with persistence) is configured.
  4. Verify token validity periods
    Check the configuration for refresh token lifespan settings. Look for 'accessTokenLifespan' or 'refreshTokenLifespan' configuration values in the realm settings or keycloak.conf.
    Affected if Long refresh token validity periods are configured (extended lifespan increases replay window).
  5. Check for token rotation policies
    Review realm settings or authentication flows for token rotation configuration. Look for whether rotating refresh tokens are enforced or if the same token can be reused.
    Affected if Token rotation is not strictly enforced or allows reuse of the same refresh token across sessions.

You are affected if revokeRefreshToken=true is enabled with persistent session storage, as this combination allows refresh token replay after server restart due to the timing mechanism reset vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to a patched Keycloak version or alternatively reduce refresh token validity periods and implement stricter token rotation. Review session storage configuration for potential timing-related issues.

Fix this in Build Of Keycloak Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-9802 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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