AUGUST 4, 2026
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Case File

CVE-2019-9803

HIGH · CVSS 7.4 EPSS 0.56%

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2019-04-26 · Last synced 2026-08-04

CyberRota Analysis

AI analysis pending.

CVE
CVE-2019-9803
Severity
HIGH
CVSS
7.4
EPSS
0.56%
Firefox

Original NVD Description

The Upgrade-Insecure-Requests (UIR) specification states that if UIR is enabled through Content Security Policy (CSP), navigation to a same-origin URL must be upgraded to HTTPS. Firefox will incorrectly navigate to an HTTP URL rather than perform the security upgrade requested by the CSP in some circumstances, allowing for potential man-in-the-middle attacks on the linked resources. This vulnerability affects Firefox < 66.