IBM SECURITY ADVISORY First Issued: Tue Mar 17 15:13:56 CDT 2026 The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/perl_advisory13.asc Security Bulletin: AIX Perl is vulnerable to a null pointer dereference (CVE-2026-24515) and an integer overflow (CVE-2026-25210) =============================================================================== SUMMARY: Vulnerabilities in Perl could cause a null pointer dereference (CVE-2026-24515) or an integer overflow (CVE-2026-25210). AIX uses Perl in various operating system components. =============================================================================== 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 = aix Fileset Lower Level Upper Level KEY --------------------------------------------------------- perl.rte 5.34.0.0 5.34.1.9 key_w_fs perl.rte 5.38.0.0 5.38.2.4 key_w_fs Note: A. Latest level of Perl 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 AIX user's guide. Example: lslpp -L | grep -i perl.rte REMEDIATION: A. FIXES IBM strongly recommends addressing the vulnerability now. The AIX and VIOS fixes can be downloaded via https from: https://aix.software.ibm.com/aix/efixes/security/perl_fix13.tar The link above is to a tar file containing this signed advisory, install 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. To extract the fixes from the tar file: tar xvf perl_fix13.tar For AIX 7.3 TL2: tar xvf perl_fix13/perl_534110 For AIX 7.3 TL3, TL4 and VIOS 4.1: tar xvf perl_fix13/perl_53825 AIX Level Fix -------------------------------------- 7.3.2 perl.rte.5.34.1.10 7.3.3 perl.rte.5.38.2.5 7.3.4 perl.rte.5.38.2.5 VIOS Level Fix -------------------------------------- 4.1.0 perl.rte.5.34.1.10 4.1.1 perl.rte.5.38.2.5 4.1.2 perl.rte.5.38.2.5 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 . perl To install the fix package: installp -aXYd . perl 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 ----------------------------------------------------------------------------------------------- da4c071fd2ca4077566ed36acae2c6124a7afca7d55a8ae7643d878343c35447 perl.rte.5.34.1.10 key_w_csum 36db3120855e3e714299f614f09a71c77412cc518bbd62f0d50a103fd3cc1ae6 perl.rte.5.38.2.5 key_w_csum The checksums below were generated using the "openssl dgst -sha512 [file]" command as the following: openssl dgst -sha512 filename ------------------------------------------------------------------------------------------------------------------------------------------------------------------ ec97acfd14213611c0713edcb12440636eadcaa885a917e54124b77eaaa744aa1955126230b2fc3bbe825016c844648b16cf837e3ae2ea45c235a45f000d8a35 perl.rte.5.34.1.10 key_4K_w_csum 5ab89079b86182ee485b2bbec05c18b6727bea801e24da46b753e13ead1b5be9972a038986d9c5da805e934b0b1f51011d6da98f558675fa5e7adb3ed0b2f1aa perl.rte.5.38.2.5 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 Support at http://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/perl_advisory13.asc.sig B. FIX AND INTERIM FIX INSTALLATION 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 fileset installation: installp -apYd . perl To install the fileset update: installp -aXYd . perl 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": 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/perl_advisory13.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: http://www.first.org/cvss/user-guide On-line Calculator v3: http://www.first.org/cvss/calculator/3.0 RELATED INFORMATION: IBM Secure Engineering Web Portal http://www.ibm.com/security/secure-engineering/bulletins.html IBM Product Security Incident Response Blog https://www.ibm.com/blogs/psirt/ Security Bulletin: AIX Perl is vulnerable to a null pointer dereference (CVE-2026-24515) and an integer overflow (CVE-2026-25210) https://www.ibm.com/support/pages/node/7266568 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Tue Mar 17 15:13:56 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.