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© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-45884

26
FAUCET Score

CVE-2021-45884 is an information disclosure vulnerability affecting Brave Desktop versions 1.17 through 1.33 before 1.33.106, specifically when CNAME-based adblocking and a SOCKS-fallback proxying extension are active. This flaw causes additional DNS requests to bypass the proxy and use system DNS settings, potentially revealing user information. Rated 7.5 HIGH on CVSS, the vulnerability has a low attack complexity and can lead to high confidentiality impact without requiring user interaction. There is no evidence of active exploitation, public exploit code, or significant community discussion, and it is not listed in CISA's KEV catalog.

Impacted Technologies

VendorProductVersion(s)CPE
>= 1.17.1, <= 1.33.106CPE matchmatch criteria
cpe:2.3:a:brave:brave:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
3.10%
Probability of exploitation in next 30 days
EPSS Percentile
86.4%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0311 is in the 76th percentile among its peer group of 51,506 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

github_advisorypatch availablevia nvd_reference
View patch

References

github.com / brave/brave-browser/issues/19070
ExploitIssue TrackingPatchThird Party Advisory
github.com / brave/brave-browser/issues/20079
Issue TrackingRelease NotesThird Party Advisory
github.com / brave/brave-core/pull/10742
PatchThird Party Advisory
hackerone.com / reports/1377864
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