Security Bulletin
Summary
The Apache Tomcat Server library is used by Power Hardware Management Console (HMC). HMC has addressed the applicable CVEs.
Vulnerability Details
CVEID: CVE-2026-59083
DESCRIPTION: Improper Handling of URL Encoding (Hex Encoding) vulnerability in Apache Tomcat's rewrite valve allowed security constraint bypass for some configurations.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.23, from 10.1.0-M1 through 10.1.56, from 9.0.0.M1 through 9.0.119, from 8.5.0 through 8.5.100. Other versions that have reached end of support may also be affected.
Users are recommended to upgrade to version 11.0.24, 10.1.57 or 9.0.120, which fix the issue.
CWE: CWE-177: Improper Handling of URL Encoding (Hex Encoding)
CVSS Source: CISA ADP
CVSS Base score: 9.1
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N)
CVEID: CVE-2026-55956
DESCRIPTION: 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.
CWE: CWE-285: Improper Authorization
CVSS Source: CISA ADP
CVSS Base score: 6.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| HMC V10.3.1050.0 | V10.3.1050.0 - V10.3.1064.1 |
| HMC V11.1.1110.0 | V11.1.1110.0 - V11.1.1112.2 |
| HMC V11.2.1120.0 | V11.2.1120.0 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now. The following fixes are available on IBM Fix Central at:
V10R3
V11R1
|
Product
|
Affected Version(s)
|
VRMF
|
APAR
|
Remediation/Fix
|
|
Power HMC
|
V10.3.1050.0 - V10.3.1064.1
|
V10.3.1064.2 x86
|
MB04531 |
MF71766 |
|
Power HMC
|
V10.3.1050.0 - V10.3.1064.1
|
V10.3.1064.2 ppc
|
MB04532 |
MF71767 |
|
Power HMC
|
V11.1.1110.0 - V11.1.1112.2
|
V11.1.1112.3 x86
|
MB04533 |
MF71769 |
|
Power HMC
|
V11.1.1110.0 - V11.1.1112.2
|
V11.1.1112.3 ppc
| MB04535 |
MF71770 |
|
Power HMC
|
V11.2.1120.0
|
V11.2.1120.1 x86
|
MB04539 |
MF71774 |
|
Power HMC
|
V11.2.1120.0
|
V11.2.1120.1 ppc
| MB04540 |
MF71775 |
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
22 Sep 2026: Initial Publication
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.
Document Location
Worldwide
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Document Information
Modified date:
22 September 2026
Initial Publish date:
22 September 2026
UID
ibm17288810