VulnerabilityModified
CVE-2017-7789
This vulnerability affects Firefox < 55.
MEDIUM 5.3EPSS 1.75%
Does this matter?
Lower severity and a low EPSS score (1.75%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.0
- 5.3 MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 1.75% probability · 78th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Affected
- mozilla/firefox
- Source
- security@mozilla.org
EPSS 1.7% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/100374Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039124Third Party Advisory, VDB Entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1074642Exploit, Issue Tracking, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-18/Vendor Advisory
- http://www.securityfocus.com/bid/100374Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039124Third Party Advisory, VDB Entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1074642Exploit, Issue Tracking, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-18/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.