CVE-2026-18840
HIGH 8.2IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to execute arbitrary code due to improper validation of an attacker-controlled pointer.
ELEVATED IMPACT
Severe if exploited (CVSS 8.2), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.1%chance of exploitation in 30 days · 2nd percentile
○ In CISA KEV
○ Public exploit / PoC
Impact if exploited
8.2CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires an admin / high-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-18840/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-18840/poc.json
Weakness (CWE)
- CWE-822: Untrusted Pointer Dereference
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Ibm | Vios | ≥ 4.1.0 and < 4.1.0.50 |
| Ibm | Vios | ≥ 4.1.1.0 and < 4.1.1.30 |
| Ibm | Vios | ≥ 4.1.2.0 and < 4.1.2.20 |
| Ibm | Aix | ≥ 7.2.5 and ≤ 7.2.5.212 |
| Ibm | Aix | ≥ 7.3.2 and ≤ 7.3.2.5 |
| Ibm | Aix | ≥ 7.3.3 and ≤ 7.3.3.2 |
| Ibm | Aix | ≥ 7.3.4 and ≤ 7.3.4.1 |
All CVSS metrics
- HIGH 8.2 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H - HIGH 8.2 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H - HIGH 7.8 v3.1 · NVD Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H