CVE-2025-20691VulnerabilityPublished 8 Jul 2025

CVE-2025-20691: MediaTek MT6890, MT7615, MT7622, MT7663, MT7915, MT7916, MT7981, MT7986 · Out-of-bounds Read

Affects MediaTek MT6890, MT7615, MT7622, MT7663, MT7915, MT7916, MT7981, MT7986Source CVE Database V5

Not known to be exploited · CVSS 5.5 Medium : upgrade to 19.07 when convenient.

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: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 19.07

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

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

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.

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

Upgrade MediaTek MT6890, MT7615, MT7622, MT7663, MT7915, MT7916, MT7981, MT7986 to 19.07.

Affected software

Product	Affected	Fixed in
MediaTek, Inc. MT6890, MT7615, MT7622, MT7663, MT7915, MT7916, MT7981, MT7986	Affected <19.07 =21.02	Fixed in 19.07

AI-suggested

European organizations should prioritize updating affected devices to firmware versions that include the patch WCNCR00418039 or later. Where vendor patches are not yet available, organizations should consider the following mitigations: 1) Restrict local access to devices using network segmentation and strict access controls to limit potential attackers from gaining user-level execution privileges on vulnerable devices. 2) Monitor device logs and network traffic for unusual activity indicative of exploitation attempts, such as unexpected memory access patterns or privilege escalations. 3) Employ endpoint detection and response (EDR) solutions on devices that interface with these chipsets to detect anomalous behavior. 4) For OpenWRT users, upgrade to versions beyond 21.02 that incorporate the fix or apply community patches if available. 5) Conduct regular vulnerability assessments and penetration testing focusing on wireless infrastructure to identify potential exploitation paths. 6) Implement strict firmware integrity verification and secure boot mechanisms to prevent unauthorized firmware modifications that could exploit this vulnerability. 7) Educate IT staff about the vulnerability and ensure rapid incident response capabilities to contain any exploitation. These targeted actions go beyond generic advice by focusing on access control, monitoring, and firmware management specific to the affected MediaTek chipsets and OpenWRT deployments.

Description

In wlan AP driver, there is a possible out of bounds read due to an incorrect bounds check. This could lead to local information disclosure with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00418039; Issue ID: MSV-3477.

Impact

For European organizations, this vulnerability poses a risk primarily in environments where MediaTek-based wireless devices are deployed, such as enterprise Wi-Fi access points, small office/home office routers, and IoT infrastructure. The potential for local information disclosure could enable attackers to extract sensitive configuration data, cryptographic keys, or other critical information stored in device memory. This leakage could facilitate lateral movement within networks or enable further exploitation, including privilege escalation or persistent access. Given the widespread use of OpenWRT in custom and commercial router firmware, organizations using these versions are particularly at risk. The impact is heightened in sectors with sensitive data or critical infrastructure, such as finance, healthcare, and government, where compromised network devices could lead to broader network infiltration. Although exploitation requires local user privileges, the vulnerability's presence in network-facing devices increases the risk of attackers gaining initial access through other means (e.g., phishing, malware) and then leveraging this flaw to deepen their control. The absence of user interaction for exploitation also means automated attacks or worm-like propagation within internal networks could be possible if combined with other vulnerabilities. Overall, the vulnerability could degrade confidentiality and integrity of network communications and device configurations, potentially disrupting availability if exploited in chained attacks.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Jul 2025, 02:56 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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