CyberSecBulletin
CVE-2026-109390NVD status: Awaiting Analysis

AnyDesk: Improper Handling of Length Parameter Inconsistency

Published Updated By the CyberSecBulletin desk

CVE-2026-109390 is a critical-severity improper handling of length parameter inconsistency vulnerability in AnyDesk, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 8.0.3 as the first without the flaw, so updating AnyDesk to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.61% chance of exploitation within 30 days, higher than 76% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update AnyDesk to 8.0.3 or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
AnyDeskAnyDesk8.0.0 up to, but not including, 8.0.38.0.3

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (mitre.org).

Official description

AnyDesk before 8.0.3 allows unauthenticated remote attackers to execute arbitrary code via a heap-based buffer overflow, as demonstrated on Linux for command execution as root without the victim approving desktop control. In the stream packet handler for mode 5 in the session protocol, a payload length value is not validated.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Handling of Length Parameter Inconsistency

The product parses a formatted message or structure, but it does not handle or incorrectly handles a length field that is inconsistent with the actual length of the associated data.

How developers prevent this class of flaw

  • When processing structured incoming data containing a size field followed by raw data, ensure that you identify and resolve any inconsistencies between the size field and the actual size of the data.
  • Do not let the user control the size of the buffer.
  • Validate that the length of the user-supplied data is consistent with the buffer size.

More Improper Handling of Length Parameter Inconsistency vulnerabilities (CWE-130)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Other vulnerabilities in AnyDesk

All AnyDesk vulnerabilities

Recent Improper Handling of Length Parameter Inconsistency vulnerabilities

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