CVE-2018-5135

Severity: high (CVSS 7.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-06-11 · updated 2026-06-17
Weakness: CWE-862

Description

WebExtensions can bypass normal restrictions in some circumstances and use "browser.tabs.executeScript" to inject scripts into contexts where this should not be allowed, such as pages from other WebExtensions or unprivileged "about:" pages. This vulnerability affects Firefox < 59.

Affected products

Mozilla Firefox: before 59.0 — fixed in 59.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 59.0. Check the vendor advisory for mitigations.

References

http://www.securityfocus.com/bid/103386
http://www.securitytracker.com/id/1040514
https://bugzilla.mozilla.org/show_bug.cgi?id=1431371
https://usn.ubuntu.com/3596-1/
https://www.mozilla.org/security/advisories/mfsa2018-06/
http://www.securityfocus.com/bid/103386
http://www.securitytracker.com/id/1040514
https://bugzilla.mozilla.org/show_bug.cgi?id=1431371
https://usn.ubuntu.com/3596-1/
https://www.mozilla.org/security/advisories/mfsa2018-06/

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