CVE-2021-22916
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 · uneditedIn Brave Desktop between versions 1.17 and 1.26.60, when adblocking is enabled and a proxy browser extension is installed, the CNAME adblocking feature issues DNS requests that used the system DNS settings instead of the extension's proxy settings, resulting in possible information disclosure.
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 confidenceIn Brave Desktop versions 1.17-1.26.60, the CNAME adblocking feature makes DNS requests that bypass proxy extension settings and use system DNS instead, potentially leaking browsing activity to the system DNS resolver when both adblocking and a proxy extension are active.
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>= 1.17.0, <= 1.26.60CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
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 checksWork through these to decide whether this CVE applies to you.
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Check Brave Desktop versionOpen Brave, click the menu icon (three lines) in the top right, select Help, then About Brave. The version number is displayed on this page.Affected if The version shown is between 1.17.0 and 1.26.60 inclusive.
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Verify CNAME adblocking is enabledGo to Brave Settings, navigate to Shields, then Ad blocking. Look for a setting labeled CNAME adblocking or similar. Check if it is turned ON or enabled.Affected if CNAME adblocking is enabled (turned on) in the Brave Shields settings.
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Confirm proxy extension is installed or activeClick the puzzle piece icon in the Brave toolbar to view extensions. Check if any proxy-related browser extensions are installed. Alternatively, go to Brave Settings, Extensions, and review the list of enabled extensions for any proxy managers or proxy-related add-ons.Affected if A proxy browser extension is installed and enabled in Brave.
All three conditions must be true simultaneously: Brave version between 1.17.0 and 1.26.60, CNAME adblocking enabled, and a proxy extension active. If any one is false, the environment is not affected by this specific vulnerability.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataUpdate Brave Desktop to version 1.26.61 or later. Until then, users should disable CNAME adblocking in Brave settings if using a proxy browser extension.
- Consultation3.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-22916 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-22916 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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