CVE-2026-18572: Auth Bypass (CVSS 6.5)

Description

Keycloak provides authorization services that allow administrators to restrict access to resources based on time policies (for example, only allowing access during business hours). A flaw was discovered where a user can include a fake time value in their authorization request that overrides the actual server time. This allows the user to bypass these time-based restrictions and access protected resources at unauthorized times.

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CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0020

Probability of exploitation

0.10%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-863 Incorrect Authorization

References

Other References

https://access.redhat.com/security/cve/CVE-2026-18572 https://bugzilla.redhat.com/show_bug.cgi?id=2509763

Frequently Asked Questions

What is CVE-2026-18572? +

Keycloak provides authorization services that allow administrators to restrict access to resources based on time policies (for example, only allowing access during business hours). A flaw was discovered where a user can include a fake time value in their authorization request that overrides the actual server time. This allows the user to bypass these time-based restrictions and access protected resources at unauthorized times. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-18572? +

CVE-2026-18572 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0020, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-18572? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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