CVE-2026-17024 is a high severity (CVSS 7.7) improper certificate validation flaw in IBM AIX 7.2 and 7.3 and PowerVM VIOS 4.1. A remote attacker could execute arbitrary code. IBM lists APARs and cumulative service packs, so update each LPAR and VIOS to the remediation level.
What's affected
IBM AIX 7.2 and 7.3, and IBM PowerVM VIOS 4.1. IBM's bulletin is a shared one that lists many AIX and VIOS vulnerabilities, and its change history shows an initial publication on 15 August 2026. The affected fileset is bos.mp64 at these levels:
- AIX 7.2.5: 7.2.5.0 to 7.2.5.212
- AIX 7.3.2: 7.3.2.0 to 7.3.2.5
- AIX 7.3.3: 7.3.3.0 to 7.3.3.2
- AIX 7.3.4: 7.3.4.0 to 7.3.4.1
IBM's remediation levels are AIX 7.2 TL05 SP13, 7.3 TL02 SP5, 7.3 TL03 SP3 and 7.3 TL04 SP2, and VIOS fix packs 4.1.0.50, 4.1.1.30 and 4.1.2.20. These service packs are cumulative. IBM lists no workaround or mitigation.
How to check if you're exposed
Check the AIX level and the affected fileset on each LPAR.
oslevel -s
lslpp -L | grep -i bos.mp64
On a VIOS, run ioslevel as padmin. If the bos.mp64 level falls in one of the ranges above, the system is affected. IBM also assigns APARs: IJ59566 for AIX 7.2.5, IJ59565 for 7.3.2, IJ59564 for 7.3.3 and IJ59563 for 7.3.4.
What to do now
- List every AIX LPAR and VIOS, with its technology level and service pack.
- Download the service pack or fix pack for your level from IBM Fix Central.
- Plan the LPAR reboot, or use Live Update on AIX where it fits, because IBM says a reboot is needed to complete the update.
- Read IBM's notes on nimsh secure and, for VIOS 4.1.0 and 4.1.1, the post-update steps for the Postgres15 migration.
- If you push updates with NIM, read IBM's nimsh secure article before the rollout.
- Recheck
oslevel -safter the update and record it.
Why it matters
The weakness is CWE-295 (Improper Certificate Validation). When software does not check a certificate fully, it can trust a peer that it should reject, and a trusted peer can send data or updates that the system acts on. IBM says this could let a remote attacker execute arbitrary code.
The vector marks complexity as high with no privileges and no user interaction, and impact is low for confidentiality and high for integrity and availability. IBM notes that applying these fixes over nimsh secure needs special steps because the master and client protocol is made more secure. CISA does not list this CVE as known exploited.
Quick check
Why does IBM mention nimsh secure?
The protocol between the NIM master and client is updated to be more secure, so IBM points to a separate article with the special steps needed to apply the patches that way.
Sources
Last reviewed: 19 October 2026.
