Medium [CVE-2026-55956] Improper Authorization Allows Security Constraint Bypass
This medium-severity Red Hat Linux advisory covers CVE-2026-55956 affecting Red Hat JBoss Web Server 6.2.4, Red Hat JBoss Web Server 6.2 on RHEL 10, Red Hat JBoss Web Server 6.2 on RHEL 8.
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
Improper Authorization vulnerability in Apache Tomcat leads to security constraints specified for the default servlet ignoring any method or method omission configured as part of the constraint.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.0.M1 through 9.0.118, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other versions that have reached end of support may also be affected.
Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119, which fix the issue. A flaw was found in Apache Tomcat where access control rules for the default servlet are improperly handled.
An attacker can exploit this issue to bypass specific HTTP method restrictions, potentially gaining unauthorized access to protected application resources. Red Hat products utilizing affected Tomcat versions are vulnerable if they rely on these method-specific security constraints.
Red Hat severity: Moderate — CVSS 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N). Weakness: CWE-551.
Affected products named by the advisory: Red Hat JBoss Web Server 6.2.4; Red Hat JBoss Web Server 6.2 on RHEL 10; Red Hat JBoss Web Server 6.2 on RHEL 8; Red Hat JBoss Web Server 6.2 on RHEL 9; and 14 more.
- 11.0.0
- 11.0.22
- 10.1.0
- 10.1.55
- 9.0.0
- 9.0.118
- 8.5.0
- 8.5.100
- 7.0.0
- 7.0.109
Official advisory · high-confidence parse· fetched 12 days ago·verify at source
- 11.0.23
- 10.1.56
- 9.0.119
- tomcat-catalina
- jws6-tomcat-0:10.1.49-15.redhat_00013.1.el10jws
- jws6-tomcat-0:10.1.49-15.redhat_00013.1.el8jws
- jws6-tomcat-0:10.1.49-15.redhat_00013.1.el9jws
- jws7-tomcat-0:11.0.21-5.redhat_00004.1.el10jws
- jws7-tomcat-0:11.0.21-5.redhat_00004.1.el8jws
- jws7-tomcat-0:11.0.21-5.redhat_00004.1.el9jws
- tomcat10-main-10.1.56-1.hum1
- tomcat11-main-11.0.23-0.1.hum1
- RHSA-2026:43402
- RHSA-2026:43401
- RHSA-2026:39189
- RHSA-2026:39188
- RHSA-2026:29203
- RHSA-2026:32960
Official advisory · high-confidence parse· fetched 12 days ago·verify at source
Mitigation checklist
- Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).
Official advisory · high-confidence parse· fetched 12 days ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.