VulnerabilityPublished 12 Aug 2025Updated 26 Feb 2026

CVE-2025-26403: Intel(R) Xeon(R) 6 processors when using Intel(R) SGX or Intel(R) TDX · Escalation of Privilege

Affects Intel(R) Xeon(R) 6 processors when using Intel(R) SGX or Intel(R) TDXSource CVE Database V5

Not known to be exploited · CVSS 4.5 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score

4.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:L/AC:H/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N

Attack Vector: Local
Attack Complexity: High
Attack Requirements: None
Privileges Required: High
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: High
Subsequent system integrity: High
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity: High: The successful attack depends on the evasion or circumvention of security-enhancing techniques in place that would otherwise hinder the attack. These include: Evasion of exploit mitigation techniques, for example, circumvention of address space randomization (ASLR) or data execution prevention (DEP) must be performed for the attack to be successful; Obtaining target-specific secrets. The attacker must gather some target-specific secret before the attack can be successful. A secret is any piece of information that cannot be obtained through any amount of reconnaissance. To obtain the secret the attacker must perform additional attacks or break otherwise secure measures (e.g. knowledge of a secret key may be needed to break a crypto channel). This operation must be performed for each attacked target.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: High: The attacker requires privileges that provide significant (e.g., administrative) control over the vulnerable system allowing full access to the vulnerable system’s settings and files.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: High: There is a total loss of confidentiality, resulting in all resources within the Subsequent System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Subsequent system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the Subsequent System. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the Subsequent System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

To mitigate CVE-2025-26403, organizations should: 1) Monitor Intel’s official advisories and apply firmware and microcode updates as soon as patches become available to address the out-of-bounds write vulnerability. 2) Restrict and tightly control privileged local access to systems running affected Intel Xeon 6 processors with SGX or TDX, employing the principle of least privilege and strong authentication mechanisms. 3) Employ robust endpoint detection and response (EDR) solutions to monitor for unusual local activity that could indicate attempts to exploit privilege escalation. 4) Use hardware and software-based security controls to limit the ability of privileged users to execute arbitrary code or modify memory in sensitive environments. 5) Conduct regular security audits and vulnerability assessments focusing on trusted execution environments and privileged user activities. 6) Consider isolating critical workloads in separate hardware or virtual environments to reduce the risk of privilege escalation impacting multiple systems. 7) Educate system administrators and security teams about the risks associated with privileged local access and the importance of timely patching.

Description

Out-of-bounds write in the memory subsystem for some Intel(R) Xeon(R) 6 processors when using Intel(R) SGX or Intel(R) TDX may allow a privileged user to potentially enable escalation of privilege via local access.

Impact

The primary impact of CVE-2025-26403 is the potential for a privileged local user to escalate their privileges beyond intended limits by exploiting an out-of-bounds write in the memory subsystem of Intel Xeon 6 processors using SGX or TDX. This could compromise the integrity of trusted execution environments, potentially allowing attackers to access or manipulate sensitive data or code protected by SGX/TDX. While the vulnerability does not enable remote exploitation or affect confidentiality or availability directly, it weakens the security model of hardware-based trusted execution, which is critical for cloud providers, enterprises running confidential workloads, and environments requiring strong isolation. If exploited, it could facilitate further attacks such as privilege escalation, unauthorized code execution, or bypassing security controls within the affected system. The requirement for high privileges and local access limits the scope to insiders or attackers who have already compromised the system to some extent. However, the erosion of trusted execution environment security could have cascading effects on data protection and compliance in sensitive sectors.

References

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