AIX: Use of Uninitialized Resource
CVE-2026-19448 is a high-severity use of uninitialized resource vulnerability in AIX from IBM, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected AIX versions: 7.2; 7.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Vios to 4.1.0.50 or 4.1.1.30 or 4.1.2.20, whichever matches your release line, or a later version.
- Read the advisory on ibm.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| IBM | AIX | 7.2; 7.3 | Not stated |
| IBM | PowerVM VIOS | 4.1 | Not stated |
| IBM | Vios | 4.1.0 up to, but not including, 4.1.0.50; 4.1.1.0 up to, but not including, 4.1.1.30; 4.1.2.0 up to, but not including, 4.1.2.20 | 4.1.0.50, 4.1.1.30, 4.1.2.20 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.5 | Medium | CNA (us.ibm.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 A stack memory corruption vulnerability exists in the AIX IPsec ESP decapsulation handler. Successful exploitation may corrupt kernel stack state and cause a system crash, resulting in denial of service.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Uninitialized Resource
The product uses or accesses a resource that has not been initialized.
How developers prevent this class of flaw
- Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
- Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
- Avoid race conditions (CWE-362) during initialization routines.
More Use of Uninitialized Resource vulnerabilities (CWE-908)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in AIX
- 7.8 High severity
- 8.8 High severity
- 7.5 High severity
- 8.8 High severity
- 7.8 High severity
- 9.9 Critical severity
Recent Use of Uninitialized Resource vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.0 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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