CyberSecBulletin
CVE-2026-25931NVD status: Deferred

vscode-spell-checker: Incorrect Default Permissions

Published Updated By the CyberSecBulletin desk

CVE-2026-25931 is a high-severity incorrect default permissions vulnerability in vscode-spell-checker from Streetsidesoftware, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected vscode-spell-checker versions: < 4.5.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.15% 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. Check which version of vscode-spell-checker you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Streetsidesoftwarevscode-spell-checker< 4.5.4Not stated

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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA (github.com).

Official description

vscode-spell-checker is a basic spell checker that works well with code and documents. Prior to v4.5.4, DocumentSettings._determineIsTrusted treats the configuration value cSpell.trustedWorkspace as the authoritative trust flag. The value defaults to true (package.json) and is read from workspace configuration each time settings are fetched. The code coerces any truthy value to true and forwards it to ConfigLoader.setIsTrusted , which in turn allows JavaScript/TypeScript configuration files ( .cspell.config.js/.mjs/.ts , etc.) to be located and executed. Because no VS Code workspace-trust state is consulted, an untrusted workspace can keep the flag true and place a malicious .cspell.config.js ; opening the workspace causes the extension host to execute attacker-controlled Node.js code with the user’s privileges. This vulnerability is fixed in v4.5.4.

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

The underlying weakness: Incorrect Default Permissions

During installation, installed file permissions are set to allow anyone to modify those files.

How developers prevent this class of flaw

  • The architecture needs to access and modification attributes for files to only those users who actually require those actions.
  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Incorrect Default Permissions vulnerabilities (CWE-276)

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

Recent Incorrect Default Permissions vulnerabilities

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