CyberSecBulletin
CVE-2026-4116NVD status: Analyzed

SMA1000: Improper Handling of Unicode Encoding

Published Updated By the CyberSecBulletin desk

CVE-2026-4116 is a high-severity improper handling of unicode encoding vulnerability in SMA1000 from SonicWall, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected SMA1000 versions: 12.4.3-03245 (platform-hotfix) and earlier versions.; 12.5.0-02283 (platform-hotfix) and earlier versions.. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Sma6210 Firmware to 12.4.3-03387 or 12.5.0-02624, whichever matches your release line, or a later version.
  2. Update Sma6200 Firmware to 12.4.3-03387 or 12.5.0-02624, whichever matches your release line, or a later version.
  3. Update Sma7200 Firmware to 12.4.3-03387 or 12.5.0-02624, whichever matches your release line, or a later version.
  4. Read the advisory on psirt.global.sonicwall.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
SonicWallSMA100012.4.3-03245 (platform-hotfix) and earlier versions.; 12.5.0-02283 (platform-hotfix) and earlier versions.Not stated
SonicWallSma6210 Firmwarebefore 12.4.3-03387; 12.5.0 up to, but not including, 12.5.0-0262412.4.3-03387, 12.5.0-02624
SonicWallSma6200 Firmwarebefore 12.4.3-03387; 12.5.0 up to, but not including, 12.5.0-0262412.4.3-03387, 12.5.0-02624
SonicWallSma7200 Firmwarebefore 12.4.3-03387; 12.5.0 up to, but not including, 12.5.0-0262412.4.3-03387, 12.5.0-02624
SonicWallSma7210 Firmwarebefore 12.4.3-03387; 12.5.0 up to, but not including, 12.5.0-0262412.4.3-03387, 12.5.0-02624
SonicWallSma8200vbefore 12.4.3-03387; 12.5.0 up to, but not including, 12.5.0-0262412.4.3-03387, 12.5.0-02624

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
HighAdministrator-level access is required first.
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:H/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).

Official description

Improper handling of Unicode encoding in SonicWall SMA1000 series appliances allows a remote authenticated SSLVPN user to bypass Workplace/Connect Tunnel TOTP authentication.

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

The underlying weakness: Improper Handling of Unicode Encoding

The product does not properly handle when an input contains Unicode encoding.

How developers prevent this class of flaw

  • Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
  • Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

More Improper Handling of Unicode Encoding vulnerabilities (CWE-176)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in SMA1000

All SMA1000 vulnerabilities

Recent Improper Handling of Unicode Encoding vulnerabilities

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