IBM SECURITY ADVISORY First Issued: Wed Sep 30 06:56:20 CDT 2026 The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/openssl_advisory49.asc Security Bulletin: Multiple vulnerabilities impact AIX due to OpenSSL =============================================================================== SUMMARY: Vulnerabilities in OpenSSL could cause excessive memory consumption (CVE-2026-54874), heap buffer overflow (CVE-2026-63072), indefinite cache growth leading to denial of service (CVE-2026-63074), invalid pointer dereference (CVE-2026-63076), and authentication forgery (CVE-2026-75803). OpenSSL is used by AIX as part of AIX's secure network communications. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2026-54874 https://www.cve.org/CVERecord?id=CVE-2026-54874 DESCRIPTION: OpenSSL DTLS may retain excessive memory when buffering future epoch records during a handshake, allowing remote attackers to amplify memory consumption and cause denial of service. CVSS Base Score: 7.5 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVEID: CVE-2026-63072 https://www.cve.org/CVERecord?id=CVE-2026-63072 DESCRIPTION: OpenSSL CMS decryption may perform an 8-byte out-of-bounds heap write when processing a crafted CMS message using AES-WRAP-PAD key unwrapping, resulting in heap corruption and denial of service. CVSS Base Score: 7.5 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVEID: CVE-2026-63074 https://www.cve.org/CVERecord?id=CVE-2026-63074 DESCRIPTION: OpenSSL CMP servers may experience unbounded memory growth when rejected requests containing extra certificates are cached indefinitely, enabling denial of service attacks. 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 CVEID: CVE-2026-63076 https://www.cve.org/CVERecord?id=CVE-2026-63076 DESCRIPTION: OpenSSL CMP password-based protection verification may dereference an invalid parameter type as a PBMParameter, allowing a remote attacker to crash a CMP client or server. CVSS Base Score: 7.5 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVEID: CVE-2026-75803 https://www.cve.org/CVERecord?id=CVE-2026-75803 DESCRIPTION: OpenSSL ChaCha20-Poly1305 and AES-OCB decryption may report success for empty ciphertexts without validating the authentication tag, potentially allowing acceptance of forged messages. 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 AFFECTED PRODUCTS AND VERSIONS: AIX 7.2, 7.3 VIOS 4.1 The vulnerabilities in the following filesets are being addressed: key_fileset = osrcaix Fileset Lower Level Upper Level KEY ------------------------------------------------------ openssl.base 3.0.0.0 3.0.21.1000 key_w_fs Note: A. OpenSSL versions below 3.0 are out-of-support. Customers are advised to upgrade to OpenSSL 3.0. To find out whether the affected filesets are installed on your systems, refer to the lslpp command found in the AIX user's guide. Example: lslpp -L | grep -i openssl.base REMEDIATION: A. FIXES IBM strongly recommends addressing the vulnerability now. The fixes can be downloaded via https from: https://aix.software.ibm.com/aix/efixes/security/openssl_fix49.tar The links above are to a tar file containing this signed advisory, fix packages, and OpenSSL signatures for each package. The fixes below include prerequisite checking. This will enforce the correct mapping between the fixes and AIX Technology Levels. Note that the tar file contains Interim fixes that are based on OpenSSL version, and AIX OpenSSL fixes are cumulative. If an OpenSSL fileset with VMRF higher than the affected level listed above is available from the web download site, then that fileset is the recommended remediation. You must be on the 'prereq for installation' level before applying the interim fix. This may require installing a new level(prereq version) first. Latest level of OpenSSL fileset is available from the web download site: https://www.ibm.com/resources/mrs/assets?source=aixbp&S_PKG=openssl AIX Level Interim Fix (*.Z) Fileset Name(prereq for installation) KEY --------------------------------------------------------------------------------------- 7.2, 7.3 54874sa.260918.epkg.Z openssl.base(3.0.21.1000) key_w_fix VIOS Level Interim Fix (*.Z) Fileset Name(prereq for installation) KEY --------------------------------------------------------------------------------------- 4.1 54874sa.260918.epkg.Z openssl.base(3.0.21.1000) key_w_fix To extract the fixes from the tar file: tar xvf openssl_fix49.tar cd openssl_fix49 Verify you have retrieved the fixes intact: The checksums below were generated using the "openssl dgst -sha256 [file]" command as the following: openssl dgst -sha256 filename KEY ----------------------------------------------------------------------------------------------------- 395e666d724961e1374844b3efd19ee037b0521dd30fbad4af25e834329df87e 54874sa.260918.epkg.Z key_w_csum The checksums below were generated using the "openssl dgst -sha512 [filename]" command as the following: openssl dgst -sha512 filename KEY ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ e2cd09da2c9999e676222d83d639ded7648200d632ae02d4aea39384ba7fb2976ac6c92dafd71eb2b90c8e87e31e89cf9862f3d6ed76eb581d6530d9cfefdf97 54874sa.260918.epkg.Z key_4K_w_csum These sums should match exactly. The OpenSSL signatures in the tar file and on this advisory can also be used to verify the integrity of the fixes. If the sums or signatures cannot be confirmed, contact IBM AIX Support at https://ibm.com/support/ and describe the discrepancy. openssl dgst -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file] openssl dgst -sha256 -verify [pubkey_file] -signature [ifix_file].sig [ifix_file] Published advisory OpenSSL signature file location: https://aix.software.ibm.com/aix/efixes/security/openssl_advisory49.asc.sig B. FIX AND INTERIM FIX INSTALLATION Interim fixes have had limited functional and regression testing but not the full regression testing that takes place for Service Packs; however, IBM does fully support them. Interim fix management documentation can be found at: https://www.ibm.com/support/pages/managing-interim-fixes-aix To preview an interim fix installation: emgr -e ipkg_name -p # where ipkg_name is the name of the # interim fix package being previewed. To install an interim fix package: emgr -e ipkg_name -X # where ipkg_name is the name of the # interim fix package being installed. WORKAROUNDS AND MITIGATIONS: None. =============================================================================== CONTACT US: Note: Keywords labeled as KEY in this document are used for parsing purposes. If you would like to receive AIX Security Advisories via email, please visit "My Notifications": https://www.ibm.com/support/mynotifications Contact IBM Support for questions related to this announcement: https://ibm.com/support/ For information on how to securely verify AIX security bulletins and fixes: https://www.ibm.com/support/pages/node/6985269 To obtain the OpenSSL public key that can be used to verify the signed advisories and ifixes: Download the key from our web page: https://aix.software.ibm.com/aix/efixes/security/systems_p_os_aix_security_pubkey.txt To verify the AIX/VIOS security bulletin: Published advisory OpenSSL signature file location: https://aix.software.ibm.com/aix/efixes/security/openssl_advisory49.asc.sig openssl dgst -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file] Please contact your local IBM AIX support center for any assistance. REFERENCES: Review this information as needed, no action required. Complete CVSS v3 Guide: https://www.first.org/cvss/user-guide On-line Calculator v3: https://www.first.org/cvss/calculator/3.0 RELATED INFORMATION: Security Bulletin: Multiple vulnerabilities impact AIX due to OpenSSL https://www.ibm.com/support/pages/node/7290182 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Wed Sep 30 06:56:20 CDT 2026 =============================================================================== *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.