CVE-2017-7839

Name: CVE-2017-7839
Creator: NVD / NIST
Published: 2018-06-11T21:29:11.78+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 1.14%

Last modified Jun 17, 2026

CVE-2017-7839 is a vulnerability of currently unknown severity. 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. EPSS estimates a 1.14% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability

1.14%

62.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	<= 56.0.2

References

http://www.securityfocus.com/bid/101832Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1039803Third Party Advisory, VDB Entry
https://bugzilla.mozilla.org/show_bug.cgi?id=1402896Issue Tracking, Permissions Required
https://www.mozilla.org/security/advisories/mfsa2017-24/Vendor Advisory
http://www.securityfocus.com/bid/101832Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1039803Third Party Advisory, VDB Entry
https://bugzilla.mozilla.org/show_bug.cgi?id=1402896Issue Tracking, Permissions Required
https://www.mozilla.org/security/advisories/mfsa2017-24/Vendor Advisory

Timeline

Published: Jun 11, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-7839?

How severe is CVE-2017-7839?

Severity scoring for CVE-2017-7839 is pending analysis. The EPSS model estimates a 1.14% probability of exploitation in the next 30 days.

How do I fix CVE-2017-7839?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2017-7839?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST