CVE-2025-48809VulnerabilityPublished 8 Jul 2025Updated 13 Feb 2026

CVE-2025-48809: Microsoft Windows 11 Version 24H2 · Processor Optimization Removal or Modification of Security-critical Code

Affects Microsoft Windows 11 Version 24H2Source CVE Database V5

Not known to be exploited · CVSS 5.5 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

5.5Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

Base metrics

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Temporal metrics

Exploit Code Maturity: Unproven
Remediation Level: Official Fix
Report Confidence: Confirmed

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

Attack Vector: Local: The vulnerable component 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 remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.
Exploit Code Maturity: Unproven: No exploit code is available, or an exploit is theoretical.
Remediation Level: Official Fix: A complete vendor solution is available. Either the vendor has issued an official patch, or an upgrade is available.
Report Confidence: Confirmed: Detailed reports exist, or functional reproduction is possible (functional exploits may provide this). Source code is available to independently verify the assertions of the research, or the author or vendor of the affected code has confirmed the presence of the vulnerability.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 Jul 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 2026-10-25.

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 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

Affected software

Product	Affected	Fixed in
Microsoft Windows 11 Version 24H2	Affected =10.0.26100.0	Fixed in–

AI-suggested

To mitigate CVE-2025-48809 effectively, European organizations should implement the following specific measures: 1) Restrict local access to Windows 11 24H2 systems by enforcing strict physical and logical access controls, including strong authentication and session locking. 2) Apply the principle of least privilege rigorously to limit the number of users with local access or low-level privileges. 3) Monitor and audit local user activities for unusual behavior that could indicate exploitation attempts, such as unauthorized kernel memory reads or privilege escalations. 4) Disable or restrict unnecessary services and features that allow local code execution or user interaction on critical systems. 5) Employ endpoint detection and response (EDR) solutions capable of detecting anomalous kernel-level activities. 6) Stay informed about Microsoft’s security advisories and apply patches immediately once available. 7) Consider deploying application whitelisting and kernel-mode code integrity policies to prevent unauthorized code modifications. 8) For high-security environments, consider isolating critical systems or using virtualization-based security features to reduce exposure. These targeted mitigations go beyond generic advice by focusing on controlling local access vectors and monitoring kernel-level activities specific to this vulnerability.

Description

Processor optimization removal or modification of security-critical code in Windows Kernel allows an authorized attacker to disclose information locally.

Impact

For European organizations, the primary impact of CVE-2025-48809 is the potential unauthorized disclosure of sensitive information on systems running Windows 11 Version 24H2. This could include leakage of kernel memory contents or other protected data accessible via the kernel. While the vulnerability requires local access, it poses a risk in environments where insider threats, compromised user accounts, or malicious local actors exist. Confidentiality breaches could lead to exposure of credentials, cryptographic keys, or other sensitive information, potentially facilitating further attacks or data exfiltration. The vulnerability does not affect system integrity or availability, so direct disruption or system compromise is less likely. However, in sectors such as finance, government, healthcare, and critical infrastructure—where data confidentiality is paramount—this vulnerability could have significant consequences. The lack of remote exploitability limits the threat surface, but organizations with shared workstations, remote desktop access, or weak local access controls remain vulnerable. The absence of patches increases the window of exposure until Microsoft releases updates. Overall, the impact is moderate but should not be underestimated in sensitive or high-security environments.

CWE-1037Processor Optimization Removal or Modification of Security-critical Code (opens in a new tab)
Base weaknessLikelihood of exploit: Low
The developer builds a security-critical protection mechanism into the software, but the processor optimizes the execution of the program such that the mechanism is removed or modified.
Attack patterns
Exploitation of Transient Instruction Execution (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2025-48809 (opens in a new tab)

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Feb 2026, 10:13 UTC

WeaknessesCWE-1037

Technical details

References

Community reviews

Related threats