Listen to this Post
CVE-2026-16874 is a privilege escalation vulnerability affecting IBM AIX version 7.2, 7.3, and IBM PowerVM VIOS 4.1. The flaw resides in improper enforcement of Role-Based Access Control (RBAC) authentication roles. Under normal operation, RBAC restricts users to only the actions permitted by their assigned roles. However, due to a logic flaw in how these roles are validated, a local attacker with low-privileged access can bypass these restrictions and execute operations reserved for the root user.
The vulnerability is classified under CWE-269: Improper Privilege Management. IBM has assigned a CVSS v3.1 base score of 7.8 (HIGH) with the vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. This indicates the attack is local (AV:L), has low complexity (AC:L), requires low privileges (PR:L), needs no user interaction (UI:N), and can lead to a complete compromise of confidentiality, integrity, and availability (C:H/I:H/A:H).
Successful exploitation would allow an attacker who already has a local user account on the system to escalate their privileges to root. This could lead to full system compromise, including reading sensitive data, modifying system files, installing malware, or disrupting operations. The vulnerability does not require network access, meaning the attacker must have physical or terminal access to the affected machine. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog as of the publication date.
IBM has released fixes for all affected versions. The recommended remediation levels are AIX 7.3 TL04 SP2, TL03 SP3, TL02 SP5, AIX 7.2 TL05 SP13, and VIOS Fix Packs 4.1.2.20, 4.1.1.30, and 4.1.0.50. These updates are cumulative and include fixes for all previously published AIX/VIOS security vulnerabilities. IBM strongly recommends applying these fixes immediately.
DailyCVE Form:
Platform: IBM AIX, PowerVM VIOS
Version: 7.2, 7.3, 4.1
Vulnerability: RBAC Privilege Escalation
Severity: HIGH (7.8 CVSS)
Date: August 19, 2026
Prediction: Patches available August 14, 2026
What Undercode Say:
Analytics indicate this vulnerability poses a significant risk in enterprise environments where AIX and PowerVM are used in critical infrastructure. The local attack vector means that once an attacker gains a foothold, full system compromise is trivial. Administrators should prioritize patching, especially on systems with many local users or where VIOS management interfaces are exposed.
Exploit: (Educational Purposes!)
The following bash commands demonstrate a conceptual approach to testing for the vulnerability. Do not use on production systems.
Check current RBAC roles and effective privileges lsuser -a roles $(whoami) whoami id Attempt to access a restricted resource (this will fail if patched) Conceptual: attempt to modify a system file owned by root echo "test" > /etc/security/test_file 2>&1 If the system is vulnerable, certain RBAC roles may allow bypass Example: A user with a specific role might be able to run restricted commands This is a conceptual representation, not a working exploit /usr/bin/su - root
Protection:
- Apply Patches Immediately: Download and install the appropriate Service Pack (SP) or Fix Pack (FP) from IBM Fix Central:
AIX 7.3 TL04 SP2, TL03 SP3, TL02 SP5
AIX 7.2 TL05 SP13
VIOS 4.1.2.20, 4.1.1.30, 4.1.0.50
- Reboot Required: After applying the SP/FP, an LPAR reboot is required unless Live Update is used on AIX.
- Review RBAC Configurations: Audit existing RBAC roles and ensure least privilege principles are enforced.
- Monitor Logs: Check system logs for suspicious local activity, especially failed or unusual role escalation attempts.
Impact:
A successful exploit allows a local attacker to gain root privileges on the affected system. This leads to:
Complete System Compromise: Full control over the AIX or VIOS host.
Data Breach: Access to all files, including sensitive customer data, configurations, and cryptographic keys.
Service Disruption: Ability to halt critical applications, delete files, or crash the system.
Lateral Movement: From a compromised VIOS, an attacker could potentially impact multiple logical partitions (LPARs) managed by that VIOS.
🎯Let’s Practice Exploiting & Learn Patching For Free:
🎓 Live Courses & Certifications:
Join Undercode Academy for Verified Certifications
🚀 Request a Custom Project:
Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by Thousands
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
