IBM SECURITY ADVISORY First Issued: Tue Nov 3 04:43:30 CST 2026 The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/perl_advisory15.asc Security Bulletin: Perl vulnerability CVE-2026-82560 (DoS) impact AIX. =============================================================================== SUMMARY: Vulnerability in Perl: Denial of Service: CVE-2026-82560 AIX uses Perl in various operating system components. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2026-82560 DESCRIPTION: Pod::Text versions before 6.1.1 for Perl allow CPU and memory exhaustion formatting a POD document whose =over nesting drives the margin to the output width. Each =over adds its indent to the margin, which wrap() subtracts from the output width to get the space available for text. When that space reaches zero, the line-splitting substitution matches the empty string, and the loop consumes no input while appending the margin padding on every pass. Formatting an attacker-supplied POD document never returns, and the output grows until memory is exhausted. 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) AFFECTED PRODUCTS AND VERSIONS: AIX 7.2, 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 5.28.0.0 5.28.1.13 key_w_fs perl.rte 5.34.0.0 5.34.1.13 key_w_fs perl.rte 5.38.0.0 5.38.2.8 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_fix15.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_fix15.tar For AIX 7.2 TL5: tar xvf perl_fix15/perl_528114 For AIX 7.3 TL2: tar xvf perl_fix15/perl_534114 For AIX 7.3 TL3, TL4 and VIOS 4.1: tar xvf perl_fix15/perl_53829 AIX Level Fix -------------------------------------- 7.2.5 perl.rte.5.28.1.14 7.3.2 perl.rte.5.34.1.14 7.3.3 perl.rte.5.38.2.9 7.3.4 perl.rte.5.38.2.9 VIOS Level Fix -------------------------------------- 4.1.0 perl.rte.5.34.1.14 4.1.1 perl.rte.5.38.2.9 4.1.2 perl.rte.5.38.2.9 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 ----------------------------------------------------------------------------------------------- 6e4a22e34be2cd5692855968918d14bff268147a5d8db50a8122fe83f149ea6d perl.rte.5.28.1.14 key_w_csum 6894c4dfeff143b3818d0705c1523a4e6f2b369af8fa8836e522f4e05b1c2bee perl.rte.5.34.1.14 key_w_csum 00c844069eaff0c964a03946c1b40a7af444880a91189cc43bd0a5ba0edc3f29 perl.rte.5.38.2.9 key_w_csum The checksums below were generated using the "openssl dgst -sha512 [file]" command as the following: openssl dgst -sha512 filename KEY ------------------------------------------------------------------------------------------------------------------------------------------------------------------ 87268489347528931463240089e4d11ecf7a9562284cdb2d42ebcd99a2a344eeb7f5048f9cb5c6976fc5fd85a3152461745e96a1b821a012eb53800355dd7348 perl.rte.5.28.1.14 key_4K_w_csum ce9a6db5ddfcd35c2f724b4c9c6e88095cf9776657c1c4d328c023c73d1398abd0f9bc2310e02523837674a4424f503492918b11ecdcddc048ab5f802006011c perl.rte.5.34.1.14 key_4K_w_csum 316fb313d6382434ffd5b6969837c81ca4c86e4de59e6e9ff79ba71cfbf9879024a3dcb4f5d7f8a61a7ddd010a12d33a1a5a8c82b9160e6eacdc4ffdcd701b81 perl.rte.5.38.2.9 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_advisory15.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_advisory15.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: Perl vulnerability CVE-2026-82560 impact AIX. https://www.ibm.com/support/pages/node/7295345 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Tue Nov 3 04:43:30 CST 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.