Local service data disclosure via stylesheet proxying
Published Mar 4, 2026 · Updated Mar 4, 2026
Origin validation errors in Dark Reader before 4.9.117 allow remote attackers to read local-server CSS through a crafted web page. The background worker fetches a cross-origin stylesheet URL supplied by a page, then places its content in an HTML style element and page session storage. A victim must open the attacker's page with the extension active, and the attacker must know a local URL that returns CSS; exposure is limited to that stylesheet data.
Summary
What happened
Origin validation errors in Dark Reader before 4.9.117 allow remote attackers to read local-server CSS through a crafted web page. The background worker fetches a cross-origin stylesheet URL supplied by a page, then places its content in an HTML style element and page session storage. A victim must open the attacker's page with the extension active, and the attacker must know a local URL that returns CSS; exposure is limited to that stylesheet data.
The record
- CVE
- CVE-2025-68467
- Published
- Mar 4, 2026
- Updated
- Mar 4, 2026
- Vendor
- Dark Reader Ltd
- Product
- Dark Reader
- Classifications
- CWE-668, CWE-200, CWE-346
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 4, 2026CVE publishedPublication date reported by the CVE source.
- Mar 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 4.9.117
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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