CVE-2017-7788

Severity: critical (CVSS 9.8 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2018-06-11 · updated 2026-06-17
Weakness: CWE-74

Description

When an "iframe" has a "sandbox" attribute and its content is specified using "srcdoc", that content does not inherit the containing page's Content Security Policy (CSP) as it should unless the sandbox attribute included "allow-same-origin". This vulnerability affects Firefox < 55.

Affected products

Mozilla Firefox: before 55.0 — fixed in 55.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 55.0. Check the vendor advisory for mitigations.

References

http://www.securityfocus.com/bid/100379
http://www.securitytracker.com/id/1039124
https://bugzilla.mozilla.org/show_bug.cgi?id=1073952
https://www.mozilla.org/security/advisories/mfsa2017-18/
http://www.securityfocus.com/bid/100379
http://www.securitytracker.com/id/1039124
https://bugzilla.mozilla.org/show_bug.cgi?id=1073952
https://www.mozilla.org/security/advisories/mfsa2017-18/

Get alerted when CVE-2017-7788 or the next vulnerability affects your stack