CVE-2017-7789

5.3 mediumEPSS 1.7%

If a server sends two Strict-Transport-Security (STS) headers for a single connection, they will be rejected as invalid and HTTP Strict Transport Security (HSTS) will not be enabled for the connection. This vulnerability affects Firefox < 55.

Severity

CVSS 3.0

5.3 medium

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS: 1.7% chance of exploitation in the next 30 days; higher than 77% of CVEs (scores of 2026-10-31)
Published: 2018-06-11
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

mozilla:firefox

References

http://www.securityfocus.com/bid/100374
http://www.securitytracker.com/id/1039124
https://bugzilla.mozilla.org/show_bug.cgi?id=1074642
https://www.mozilla.org/security/advisories/mfsa2017-18/
http://www.securityfocus.com/bid/100374

Check your stack JSON