VulnerabilityPublished 2 Dec 2025

CVE-2025-20788: MediaTek MT6991, MT8196 · Improper Access Control for Register Interface

Affects MediaTek MT6991, MT8196Source CVE Database V5

Not known to be exploited · CVSS 4.4 Medium.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

4.4Medium

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

EPSS: 0.07% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L

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

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Dec 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

European organizations should implement the following specific mitigations: 1) Monitor vendor advisories and apply the official patch (ALPS10117735) as soon as it becomes available to eliminate the vulnerability. 2) Restrict installation of untrusted or unsigned applications on devices using the affected chipsets to reduce the risk of malicious code triggering the vulnerability. 3) Enforce strict device access controls, including limiting physical and local access to trusted users only. 4) Employ mobile device management (MDM) solutions to monitor and control application behavior and permissions on Android 15.0 devices. 5) Conduct regular security audits of devices incorporating MediaTek MT6991 and MT8196 chipsets to detect anomalous behavior indicative of exploitation attempts. 6) Educate users about the risks of installing unknown applications and the importance of user interaction in exploitation to reduce inadvertent triggering of the vulnerability. 7) For critical environments, consider network segmentation and endpoint protection to isolate vulnerable devices and limit potential impact.

Description

In GPU pdma, there is a possible memory corruption due to a missing permission check. This could lead to local denial of service with no additional execution privileges needed. User interaction is needed for exploitation. Patch ID: ALPS10117735; Issue ID: MSV-4539.

Impact

For European organizations, the primary impact of this vulnerability is the potential for local denial of service on devices using the affected MediaTek chipsets. This could disrupt operations on mobile devices, embedded systems, or IoT devices running Android 15.0 with these chipsets. While the vulnerability does not allow attackers to gain elevated privileges or access sensitive data, the DoS condition could affect availability of critical applications or services, particularly in environments relying on mobile or edge computing devices. The requirement for user interaction and local access limits the attack surface but does not eliminate risk in scenarios where untrusted applications or users have device access. Industries such as telecommunications, manufacturing, and critical infrastructure using MediaTek-powered devices may experience operational interruptions. Additionally, consumer devices prevalent in European markets could be affected, potentially impacting end-user experience and trust.

CWE-1262Improper Access Control for Register Interface (opens in a new tab)
Base weakness
The product uses memory-mapped I/O registers that act as an interface to hardware functionality from software, but there is improper access control to those registers.
Architecture and Design
Design proper policies for hardware register access from software.
Implementation
Ensure that access control policies for register access are implemented in accordance with the specified design.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
Third Party Javascript Management (opens in a new tab)
Virtual Patching (opens in a new tab)
OWASP ASVS 4.0.3
V1.4.4 (opens in a new tab)
V1.4.5 (opens in a new tab)
V1.10.1 (opens in a new tab)
Attack patterns
Exploitation of Improperly Controlled Registers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

corp.mediatek.com/product-security-bulletin/December-2025 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 9 Dec 2025, 04:38 UTC

WeaknessesCWE-1262

Technical details

References

Community reviews

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