Vulnerability in Keycloak identity management service (CVE-2026-18218)
Summary
Vulnerability in Keycloak identity management service (CVE-2026-18218). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
A flaw was found in the TokenManager component of the Keycloak identity management service. When an administrator attempts to revoke tokens for a specific application (client) using a "not-before" policy, the revocation may be silently ignored if the overall security realm already has an older, non-zero revocation policy in place. This issue can allow previously issued tokens to remain valid for refreshing sessions and accessing user information even after an administrator has attempted to invalidate them.
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Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-18218 has been found in Keycloak identity management service.
Risk of unauthorized operations or information disclosure. CVSS score: 4.2/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Keycloak identity management service CVE-2026-18218" on the vendor's site.
CVE-2026-18218 (Keycloak identity management service) — CWE-862 / CVSS v3 4.2
Attack vector: remote (network-reachable) / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-862) exists in Keycloak identity management service.
Check the vendor advisory for the affected versions of Keycloak identity management service.
Severity: Medium (CVSS 4.2/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Keycloak identity management service を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory access.redhat.com
- advisory bugzilla.redhat.com
- web nvd.nist.gov
- web github.com
- web access.redhat.com
- web access.redhat.com