CVE-2020-26958

Mozilla: Requests intercepted through ServiceWorkers lacked MIME type restrictions

Published Dec 9, 2020 CVSS 3.1 · 6.1 Medium EPSS 1.4% KEV · Not listed
Description
Firefox did not block execution of scripts with incorrect MIME types when the response was intercepted and cached through a ServiceWorker. This could lead to a cross-site script inclusion vulnerability, or a Content Security Policy bypass. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-2457-1 firefox-esr security update
Debian DLA Debian DLA DLA-2464-1 thunderbird security update
Debian DSA Debian DSA DSA-4793-1 firefox-esr security update
Debian DSA Debian DSA DSA-4796-1 thunderbird security update
EUVD EUVD EUVD-2020-19482 Firefox did not block execution of scripts with incorrect MIME types when the response was intercepted and cached through a ServiceWorker. This could lead to a cross-site script inclusion vulnerability, or a Content Security Policy bypass. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
Ubuntu USN Ubuntu USN USN-4637-1 Firefox vulnerabilities
Ubuntu USN Ubuntu USN USN-4637-2 Firefox vulnerabilities
Ubuntu USN Ubuntu USN USN-4647-1 Thunderbird vulnerabilities
History

No history.

Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Aug 4, 2024, 4:03 PM
Reserved
Oct 12, 2020, 12:00 AM
Status
Modified
Published
Dec 9, 2020, 1:15 AM
Modified
Jun 17, 2026, 3:08 AM
Severity
Moderate
Public date
Nov 17, 2020, 12:00 AM