CVE-2020-26958
6.1
MEDIUM
CVSS 3.1
EPSS 0.66%
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.
How to fix CVE-2020-26958
To remediate CVE-2020-26958, upgrade the affected package to a fixed version below.
- —upgrade to 78.5.0esr-1 or later
- —upgrade to 1:78.5.0-1 or later
Is CVE-2020-26958 being exploited?
Low — EPSS is 0.7%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 78.5.0esr-1
- from 0, < 1:78.5.0-1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |