IBM SECURITY ADVISORY First Issued: Wed Feb 18 08:49:11 CST 2026 The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/bind_advisory29.asc Security Bulletin: Multiple vulnerabilities impact AIX due to ISC BIND (CVE-2025-40778, CVE-2025-40780, CVE-2025-8677) =============================================================================== SUMMARY: Vulnerabilities in ISC BIND could allow an attacker to inject forged data into the cache (CVE-2025-40778), predict the source port and query ID that BIND will use (CVE-2025-40780), or cause CPU exhaustion (CVE-2025-8677). AIX uses ISC BIND as as part of its DNS functions. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2025-40778 https://www.cve.org/CVERecord?id=CVE-2025-40778 DESCRIPTION: Under certain circumstances, BIND is too lenient when accepting records from answers, allowing an attacker to inject forged data into the cache. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1. CVSS Base Score: 8.6 CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N) CVEID: CVE-2025-40780 https://www.cve.org/CVERecord?id=CVE-2025-40780 DESCRIPTION: In specific circumstances, due to a weakness in the Pseudo Random Number Generator (PRNG) that is used, it is possible for an attacker to predict the source port and query ID that BIND will use. This issue affects BIND 9 versions 9.16.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.16.8-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1. CVSS Base Score: 8.6 CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N) CVEID: CVE-2025-8677 https://www.cve.org/CVERecord?id=CVE-2025-8677 DESCRIPTION: Querying for records within a specially crafted zone containing certain malformed DNSKEY records can lead to CPU exhaustion. This issue affects BIND 9 versions 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1. CVSS Base Score: 7.5 CVSS Environmental Score*: Undefined 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 are being addressed in the following filesets: key_fileset = aix Fileset Lower Level Upper Level KEY ---------------------------------------------------------- bind.rte 7.1.916.0 7.1.916.4800 key_w_fs bind.rte 7.2.916.0 7.2.916.4801 key_w_fs bind.rte 7.2.918.0 7.2.918.2802 key_w_fs bind.rte 7.3.916.0 7.3.916.4800 key_w_fs bind.rte 7.3.918.0 7.3.918.2802 key_w_fs Note: A. Latest level of BIND 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 bind.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/bind_fix29.tar The fileset update has a dependency on OpenSSL 3.0. OpenSSL 3.0 may be downloaded from: https://www.ibm.com/resources/mrs/assets?source=aixbp 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 bind_fix29.tar For AIX 7.2 and VIOS 3.1 (requires OpenSSL 3.0): tar xvf bind_fix29/72bind918.tar For AIX 7.3 and VIOS 4.1: tar xvf bind_fix29/73bind918.tar 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 . bind To install the fix package: installp -aXYd . bind 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 --------------------------------------------------------------------------------------- 789d3ee5df0e7a223c35ef0b27c1e6fc1bdcac01606039a6bcf74182abb14244 72bind.rte key_w_csum 6f81f94ca66347929783bb6b6ab6ba8ae2e0e22288e6ecd8a5d887d02f0110ee 73bind.rte key_w_csum openssl dgst -sha512 filename ---------------------------------------------------------------------------------------------------------------------------------------------------------- 12202afcf9f26d286c9421ecbc92160d6ce1b4adcab824175d15633b3982f1375ef0caef5646462046cef020ef8fd944af6cfd4442e52e6d4fc6a0c2b8910d00 72bind.rte key_4K_w_csum db13307fc9efadc97e4b5e6609713bc9082a24395d2177bf67bb596678611379e66631d07ee8ababcad4afa8807a88ef2a65b66207d2e4271a60d1cf222ac220 73bind.rte 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/bind_advisory29.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 a fix installation: installp -a -d fix_name -p all # where fix_name is the name of the # fix package being previewed. To install a fix package: installp -a -d fix_name -X all # where fix_name is the name of the # fix package being installed. 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/bind_advisory29.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: Multiple vulnerabilities impact AIX due to ISC BIND (CVE-2025-40778, CVE-2025-40780, CVE-2025-8677) https://www.ibm.com/support/pages/node/7261171 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Wed Feb 18 08:49:11 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.