[NEW] [high] Keycloak: Multiple vulnerabilities

highCVE-2026-15571 CVE-2026-18963 CVE-2026-45292 CVE-2026-59888 CVE-2026-59889

An attacker can exploit multiple vulnerabilities in Keycloak to bypass security measures and thereby take over user accounts.

CSIRTS triage

vendor: Keycloak product: Keycloak Authentication bypass

What: Multiple vulnerabilities in Keycloak allow security mechanism bypass leading to unauthorized user account takeover.
Who is affected: Keycloak deployments running vulnerable versions.
Urgency: High severity; allows account takeover via authentication bypass.
Action: Apply Keycloak security patches for the five CVEs listed to prevent account compromise.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: high
Published: 2026-08-19
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2915

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-155710.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 24% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-189630.39% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 32% of all EPSS-scored CVEs.
Moderate exploitation riskCVE-2026-452921.1% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 63% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-598880.25% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 16% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-598890.35% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 28% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-15571	coverage & exploitation status	NVD · CVE.org
CVE-2026-18963	coverage & exploitation status	NVD · CVE.org
CVE-2026-45292	coverage & exploitation status	NVD · CVE.org
CVE-2026-59888	coverage & exploitation status	NVD · CVE.org
CVE-2026-59889	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Keycloak

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

medium[UPDATE] [medium] Keycloak: Multiple vulnerabilitiescert-bund · 2026-08-19
medium[NEW] [UNPATCHED] [medium] Keycloak: Multiple vulnerabilitiescert-bund · 2026-08-19
medium[NEW] [UNPATCHED] [medium] Keycloak: Multiple vulnerabilities allow information disclosurecert-bund · 2026-08-19
medium[NEW] [UNPATCHED] [medium] Keycloak: Vulnerability allows information disclosurecert-bund · 2026-08-19
highCVE-2026-15571: A flaw was found in the legacy client-initiated account-linking endpoint of Keycloak, a widely…nvd · 2026-08-18
criticalCVE-2026-18963: A flaw was found in the reset-credentials flow of the keycloak-services component, which is th…nvd · 2026-08-18