CVE-2026-66422
HIGHDescription
Improper Authorization vulnerability in Apache Tomcat cause by security-role-ref definitions being incorrectly used as role aliases within the Realm in additional to the correct usage with Request.isUserInRole(). This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.25 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.46 through 8.5.100, from 7.0.97 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 45% of all known CVEs.
References
Related Vulnerabilities
Other CWE-285 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-29927 | Critical | 9.1 | 99% | - | Fix |
| CVE-2023-32707 | High | 8.8 | 79% | - | Fix |
| CVE-2021-28799 | Critical | 10.0 | 78% | KEV + Ransom | Fix |
| CVE-2023-48241 | High | 7.5 | 73% | - | Fix |
| CVE-2023-22480 | High | 7.3 | 67% | - | Fix |
| CVE-2022-3229 | Critical | 9.8 | 66% | - | - |
Common questions
How do I fix CVE-2026-66422?
Upgrade tomcat to 10.1.58 or later.
Is CVE-2026-66422 being actively exploited?
Not that we know of. CVE-2026-66422 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.57% is the estimated probability that it will be exploited in the next 30 days. That is higher than 45% of all scored CVEs.
How severe is CVE-2026-66422?
CVE-2026-66422 has a CVSS v3 base score of 8.1, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-66422 affect?
Published advisories record a fix for tomcat (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-27.