Filtering-rule manipulation via cleartext JSON downloads
Published Jun 3, 2026 · Updated Jun 3, 2026
Cleartext transmission in Securly Chrome Extension 3.0.7 allows man-in-the-middle attackers to alter filtering data over HTTP. The extension's Fetch API requests crisis-alert keyword and filtering-rule JSON from HTTP endpoints instead of applying TLS as it does for IWF and CIPA data. Exploitation requires an on-path position, enabling interception or modification of downloaded configuration and consequent exposure to blocked content or improper blocking.
Summary
What happened
Cleartext transmission in Securly Chrome Extension 3.0.7 allows man-in-the-middle attackers to alter filtering data over HTTP. The extension's Fetch API requests crisis-alert keyword and filtering-rule JSON from HTTP endpoints instead of applying TLS as it does for IWF and CIPA data. Exploitation requires an on-path position, enabling interception or modification of downloaded configuration and consequent exposure to blocked content or improper blocking.
The record
- CVE
- CVE-2026-8874
- Published
- Jun 3, 2026
- Updated
- Jun 3, 2026
- Vendor
- Securly
- Product
- Securly Chrome Extension
- Classifications
- CWE-319, T1557
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 3, 2026CVE publishedPublication date reported by the CVE source.
- Jun 3, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <3.0.7
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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