Security Bulletin
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
DESCRIPTION: In libexpat before 2.7.4, XML_ExternalEntityParserCreate does not copy unknown encoding handler user data.
CWE: CWE-476: NULL Pointer Dereference
CVSS Source: NVD
CVSS Base score: 2.5
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
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.
CWE: CWE-190: Integer Overflow or Wraparound
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| AIX | 7.3 |
| VIOS | 4.1 |
The vulnerabilities in the following filesets are being addressed:
| Fileset | Lower Level | Upper Level |
| python3.9.base | 3.9.0.0 | 3.9.24.0 |
| python3.11.base | 3.11.0.0 | 3.11.14.0 |
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/Fixes
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 |
| 7.3 | python-3.11.14.1.tar.Z |
| VIOS Level | Fix |
| 4.1 | python-3.11.14.1.tar.Z |
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 |
| bf0f413bafd74278ca208ac2b144f016e95efa8c71cb314d7b71a6d6340d8d6d | python-3.11.14.1.tar.Z |
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 |
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
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
17 Mar 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:
17 March 2026
Initial Publish date:
17 March 2026
UID
ibm17266572