in Alias Checking Trusted Module for some…: Improper Access Control
CVE-2026-20898 is a high-severity improper access control vulnerability in in Alias Checking Trusted Module for some Intel(R) Xeon(R) processors may allow an escalation of privilege. Startup code and SMM adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are not present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (high) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (high) and availability (none) impacts., with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. Affected in Alias Checking Trusted Module for some Intel(R) Xeon(R) processors may allow an escalation of privilege. Startup code and SMM adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are not present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (high) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (high) and availability (none) impacts. versions: See references. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.13% 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
- Check which version of in Alias Checking Trusted Module for some Intel(R) Xeon(R) processors may allow an escalation of privilege. Startup code and SMM adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are not present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (high) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (high) and availability (none) impacts. you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on intel.com for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE; 35 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.5 | High | CNA (intel.com) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
Improper access control in the firmware for some in Alias Checking Trusted Module for some Intel(R) Xeon(R) processors may allow an escalation of privilege. Startup code and SMM adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are not present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (high) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (high) and availability (none) impacts.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Recent Improper Access Control vulnerabilities
- 7.8 High severity
- 7.4 High severity
- 7.0 High severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
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