CVE-2025-9688VulnerabilityPublished 30 Aug 2025Updated 2 Sep 2025

CVE-2025-9688: Mupen64Plus · Integer Overflow

Affects Mupen64PlusSource CVE Database V5

Not known to be exploited · CVSS 2.3 Low.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

2.3Low

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 20% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

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

Threat metrics

Exploit Maturity: POC

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system 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 to the Vulnerable System.
Vulnerable system 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 Vulnerable System 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 Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable 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.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 30 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 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
Mupen64Plus	Affected =2.0 =2.1 =2.2 =2.3 =2.4 =2.5 =2.6.0	Fixed in–

AI-suggested

To mitigate the risk posed by CVE-2025-9688, European organizations should take the following specific actions: 1) Identify and inventory all instances of Mupen64Plus installed on corporate or managed devices, including versions up to 2.6.0. 2) Apply the official patch corresponding to commit 3984137fc0c44110f1ef876adb008885b05a6e18 promptly to all affected versions to eliminate the integer overflow vulnerability. 3) Restrict the use of emulators like Mupen64Plus on corporate networks and endpoints unless explicitly required, and enforce application whitelisting policies to prevent unauthorized installation or execution. 4) Educate users about the risks of running untrusted software and the importance of applying updates, especially for software that can be remotely exploited. 5) Monitor network traffic and endpoint behavior for unusual activity that could indicate exploitation attempts, focusing on the network ports and protocols used by Mupen64Plus. 6) Implement endpoint detection and response (EDR) solutions capable of detecting anomalous behavior related to emulator processes. 7) Maintain a robust patch management process to ensure timely updates of all software, including less common applications like emulators. These targeted measures go beyond generic advice by focusing on the specific software and exploitation vectors involved.

Description

A security vulnerability has been detected in Mupen64Plus up to 2.6.0. The affected element is the function write_is_viewer of the file src/device/cart/is_viewer.c. The manipulation leads to integer overflow. It is possible to initiate the attack remotely. The attack is considered to have high complexity. The exploitability is described as difficult. The exploit has been disclosed publicly and may be used. The identifier of the patch is 3984137fc0c44110f1ef876adb008885b05a6e18. To fix this issue, it is recommended to deploy a patch.

Impact

For European organizations, the direct impact of CVE-2025-9688 is likely limited due to the nature of the affected software—Mupen64Plus is primarily a consumer-grade emulator used for gaming rather than critical business infrastructure. However, organizations with employees or users who run this emulator on corporate devices could face risks such as unauthorized code execution or data corruption if the vulnerability is exploited. This could lead to minor confidentiality or integrity issues, or potentially disrupt availability of the emulator application. The low severity and high complexity of exploitation reduce the likelihood of widespread impact. Nonetheless, organizations should be aware that any remote code execution or overflow vulnerability can be leveraged as part of a multi-stage attack chain, especially if combined with other vulnerabilities or social engineering tactics. Additionally, organizations involved in software development, gaming, or digital preservation that utilize Mupen64Plus might face higher risk exposure. Overall, the threat to European organizations is low but not negligible, particularly in environments where gaming software is permitted or used.

References

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