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ChromeWeb browser · Google

CVE-2026-12034

HIGH · 8.3 CVSS v3.1 Published 2026-06-11
Fix available
A fix is available. Upgrade to 149.0.7827.115 or later.
See remediation →
90/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Insufficient validation of untrusted input in Linux Toolkit Theming in Google Chrome on Linux prior to 149.0.7827.115 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a malicious file. (Chromium security severity: High)

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Insufficient validation of untrusted input in the Linux Toolkit Theming component of Google Chrome on Linux allows a remote attacker who has already compromised the renderer process to potentially escape the sandbox via a malicious file. This is a secondary attack requiring prior renderer compromise.

MitigationUpdate Google Chrome on Linux to version 149.0.7827.115 or later to patch the theming validation vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ChromeWeb browser
Affected:< 149.0.7827.115

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Chrome is installed on Linux
    Run 'google-chrome --version' or 'google-chrome-stable --version' in terminal to verify Chrome is installed
    Affected if The command returns a version number indicating Chrome is installed on a Linux system
  2. Check installed Chrome version
    Run 'google-chrome --version' and note the full version string (e.g., 149.0.7827.114)
    Affected if The version returned is less than 149.0.7827.115
  3. Verify Linux Toolkit Theming component is in use
    This component is part of Chrome's theming system on Linux and is enabled by default when Chrome runs on Linux - no manual configuration check required
    Affected if Chrome is running on Linux with a version below 149.0.7827.115 and the theming component is active (default state)
  4. Confirm the vulnerable component is present
    The Linux Toolkit Theming component ships with Chrome on Linux and cannot be disabled through user settings - it is part of the standard Chrome installation
    Affected if Chrome on Linux is running any version below 149.0.7827.115

A user is affected if they are running Google Chrome on Linux with a version lower than 149.0.7827.115, as the Linux Toolkit Theming component contains the input validation flaw that could enable a sandbox escape.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 149.0.7827.115 or later
Fixed in 149.0.7827.115
Interim mitigation

Update Google Chrome on Linux to version 149.0.7827.115 or later to patch the theming validation vulnerability.

Recommended fix High confidence

Chrome 149.0.7827.115 or later

  1. Check the current Chrome version by navigating to chrome://settings/help
  2. Download Chrome 149.0.7827.115 or later from the official Google Chrome website (google.com/chrome)
  3. Install the updated Chrome version using the downloaded installer or system package manager
  4. Restart Chrome to apply the update
  5. Verify the version by checking chrome://settings/help shows version 149.0.7827.115 or higher

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Chrome Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-12034 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data