CVE-2017-7839

Severity: medium (CVSS 6.1 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% 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-79

Description

Control characters prepended before "javascript:" URLs pasted in the addressbar can cause the leading characters to be ignored and the pasted JavaScript to be executed instead of being blocked. This could be used in social engineering and self-cross-site-scripting (self-XSS) attacks where users are convinced to copy and paste text into the addressbar. This vulnerability affects Firefox < 57.

Affected products

Mozilla Firefox: through 56.0.2

References

http://www.securityfocus.com/bid/101832
http://www.securitytracker.com/id/1039803
https://bugzilla.mozilla.org/show_bug.cgi?id=1402896
https://www.mozilla.org/security/advisories/mfsa2017-24/
http://www.securityfocus.com/bid/101832
http://www.securitytracker.com/id/1039803
https://bugzilla.mozilla.org/show_bug.cgi?id=1402896
https://www.mozilla.org/security/advisories/mfsa2017-24/

Get alerted when CVE-2017-7839 or the next vulnerability affects your stack