Security Bulletin
Summary
The OpenSSL package is used by the Virtualization Management Interface in PowerVM to support network communication with the Hardware Management Console. This bulletin provides a remediation for the impacted vulnerability, CVE-2025-66199, by upgrading PowerVM and thus addressing the exposure to the OpenSSL vulnerability.
Vulnerability Details
CVEID: CVE-2025-66199
DESCRIPTION: Issue summary: A TLS 1.3 connection using certificate compression can be
forced to allocate a large buffer before decompression without checking
against the configured certificate size limit.
Impact summary: An attacker can cause per-connection memory allocations of
up to approximately 22 MiB and extra CPU work, potentially leading to
service degradation or resource exhaustion (Denial of Service).
In affected configurations, the peer-supplied uncompressed certificate
length from a CompressedCertificate message is used to grow a heap buffer
prior to decompression. This length is not bounded by the max_cert_list
setting, which otherwise constrains certificate message sizes. An attacker
can exploit this to cause large per-connection allocations followed by
handshake failure. No memory corruption or information disclosure occurs.
This issue only affects builds where TLS 1.3 certificate compression is
compiled in (i.e., not OPENSSL_NO_COMP_ALG) and at least one compression
algorithm (brotli, zlib, or zstd) is available, and where the compression
extension is negotiated. Both clients receiving a server CompressedCertificate
and servers in mutual TLS scenarios receiving a client CompressedCertificate
are affected. Servers that do not request client certificates are not
vulnerable to client-initiated attacks.
Users can mitigate this issue by setting SSL_OP_NO_RX_CERTIFICATE_COMPRESSION
to disable receiving compressed certificates.
The FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue,
as the TLS implementation is outside the OpenSSL FIPS module boundary.
OpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue.
OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.
CWE: CWE-789: Memory Allocation with Excessive Size Value
CVSS Source: CISA ADP
CVSS Base score: 5.9
CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| Virtualization Management Interface | FW1110.00 - FW1120.20 |
| Virtualization Management Interface | FW1060.00 - FW1060.61 |
Remediation/Fixes
Power 10
1) IBM Power System S1022 (9105-22A)
2) IBM Power System S1024 (9105-42A)
3) IBM Power System S1022s (9105-22B)
4) IBM Power System S1014 (9105-41B)
5) IBM Power System L1022 (9786-22H)
6) IBM Power System L1024 (9786-42H)
7) IBM Power System E1050 (9043-MRX)
8) IBM Power System S1012 (9028-21B)
The images mentioned above can be located at IBM Fix Central : https://www.ibm.com/support/fixcentral/
Power 11
1) IBM Power System S1122 (9824-22A)
2) IBM Power System S1124 (9824-42A)
3) IBM Power System S1122s (9824-22B)
4) IBM Power System S1114 (9824-41B)
5) IBM Power System L1122 (9856-22H)
6) IBM Power System L1124 (9856-42H)
7) IBM Power System E1150 (9043-MRU)
The images mentioned above can be located at IBM Fix Central : https://www.ibm.com/support/fixcentral/
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
30 Jun 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:
30 June 2026
Initial Publish date:
30 June 2026
UID
ibm17278581