IBM SECURITY ADVISORY First Issued: Tue Mar 17 15:18:12 CDT 2026 The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/python_advisory18.asc Security Bulletin: AIX Python is vulnerable to a null pointer dereference (CVE-2026-24515) and an integer overflow (CVE-2026-25210) =============================================================================== SUMMARY: Vulnerabilities in Python could cause a null pointer dereference (CVE-2026-24515) or an integer overflow (CVE-2026-25210). Python is used by AIX as part of Ansible node management automation. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2026-24515 https://www.cve.org/CVERecord?id=CVE-2026-24515 DESCRIPTION: In libexpat before 2.7.4, XML_ExternalEntityParserCreate does not copy unknown encoding handler user data. CVSS Base Score: 2.5 CVSS Environmental Score*: Undefined CVSS Vector:(CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L) CVEID: CVE-2026-25210 https://www.cve.org/CVERecord?id=CVE-2026-25210 DESCRIPTION: In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation. CVSS Base Score: 6.9 CVSS Environmental Score*: Undefined CVSS Vector:(CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L) AFFECTED PRODUCTS AND VERSIONS: AIX 7.3 VIOS 4.1 The vulnerabilities in the following filesets are being addressed: key_fileset = osrcaix Fileset Lower Level Upper Level KEY ------------------------------------------------------ python3.9.base 3.9.0.0 3.9.23.0 key_w_fs python3.11.base 3.11.0.0 3.11.14.0 key_w_fs Note: A. Python 3.9 is out-of-support. Considering long term support, it is advised to upgrade to Python 3.11. B. Latest level of Python fileset is available from the web download site: https://www.ibm.com/resources/mrs/assets?source=aixbp 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 python3.9.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/python_fix18.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. AIX Level Fix (*.Z) KEY ----------------------------------------------- 7.3 python-3.11.14.1.tar.Z key_w_fix VIOS Level Fix (*.Z) KEY ----------------------------------------------- 4.1 python-3.11.14.1.tar.Z key_w_fix To extract the fixes from the tar file: tar xvf python_fix18.tar cd python_fix18 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 --------------------------------------------------------------------------------------------------- bf0f413bafd74278ca208ac2b144f016e95efa8c71cb314d7b71a6d6340d8d6d python-3.11.14.1.tar.Z key_w_csum The checksums below were generated using the "openssl dgst -sha512 [filename]" command as the following: openssl dgst -sha512 filename ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ d403783930e215dac1a2611cd07117d9f9794379176e1f82238805f61bbef2767fe787298bdc85235b88ba26413ced5c61bd228a669852dcb1b4ed33476b5826 python-3.11.14.1.tar.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/python_advisory18.asc.sig B. FIX AND INTERIM FIX INSTALLATION To extract the fixes from the tar file: zcat python-3.11.14.1.tar.Z | tar xvf - IMPORTANT: If possible, it is recommended that a mksysb backup of the system be created. Verify it is both bootable and readable before proceeding. To preview the fix installation: installp -apYd . python3.11.base To install the fix package: installp -aXYd . python3.11.base 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": http://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/python_advisory18.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: 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: AIX Python is vulnerable to a null pointer dereference (CVE-2026-24515) and an integer overflow (CVE-2026-25210) https://www.ibm.com/support/pages/node/7266572 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Tue Mar 17 15:18:12 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.