VulnerabilityPublished 6 Nov 2025Updated 8 Dec 2025

CVE-2025-27916: AnyDesk · Authentication Bypass by Spoofing

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in 9.0.6 : patch Windows soon.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Affects: Windows before 9.0.6
Patch: Available – fixed in 9.0.6, 8.0.0

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

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

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: 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: 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: None: There is no loss of confidentiality within the impacted component.
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 impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 6 Nov 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

1. 2. If you cannot patch yet, restrict or disable direct IP-based connections in AnyDesk configurations to prevent exploitation of the spoofing vector. 3. Implement network-level controls such as firewall rules or VPN requirements to limit AnyDesk traffic to trusted endpoints only. 4. Employ multi-factor authentication (MFA) on AnyDesk accounts and related systems to reduce the risk of unauthorized access even if spoofing occurs. 5. Conduct regular audits of remote access logs to detect unusual connection patterns or unexpected AnyDesk IDs. 6. Educate IT and security teams about this vulnerability to ensure rapid response and incident handling if suspicious activity is detected. 7. Coordinate with AnyDesk support or vendor channels for official patches and security advisories. 8. Consider alternative remote access solutions with stronger authentication and session integrity guarantees if immediate patching is not feasible.

Description

An issue was discovered in AnyDesk for Windows before 9.0.6 and AnyDesk for Android before 8.0.0. When the connection between two clients is established via an IP address, it is possible to manipulate the data and spoof the AnyDesk ID.

Impact

For European organizations, this vulnerability poses a significant risk to the integrity of remote access sessions, especially in sectors heavily reliant on AnyDesk for remote support, administration, or teleworking. Attackers exploiting this flaw could impersonate legitimate users, potentially gaining unauthorized control over systems or injecting malicious commands. This could lead to unauthorized changes in critical systems, data manipulation, or lateral movement within networks. The absence of required privileges or user interaction lowers the barrier for exploitation, increasing the threat level. Organizations in finance, healthcare, government, and critical infrastructure sectors are particularly vulnerable due to the sensitive nature of their operations and the widespread use of remote access tools. The impact is heightened in environments where IP-based connections are common or where network segmentation is weak, facilitating easier exploitation. Additionally, the lack of confidentiality impact means data exfiltration is less likely directly from this vulnerability, but the integrity compromise could enable further attacks or fraud.

CWE-290Authentication Bypass by Spoofing (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
OWASP Cheat Sheets
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V3.5.1 (opens in a new tab)
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
Attack patterns
Creating a Rogue Certification Authority Certificate (opens in a new tab)
Web Services API Signature Forgery Leveraging Hash Function Extension Weakness (opens in a new tab)
Signature Spoof (opens in a new tab)
Signature Spoofing by Misrepresentation (opens in a new tab)
Session Credential Falsification through Prediction (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 8 Dec 2025, 17:50 UTC

WeaknessesCWE-290

Technical details

References

Community reviews

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