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CVE-2019-9803

N/A
Published: April 26, 2019 at 04:13 PM UTC
Updated: June 17, 2026 at 02:44 AM UTC
1 product affected across 1 vendorFirefox

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Severity
N/A
Exploit prediction
EPSS 0.6%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Firefox· Mozilla
95%
v < 66
Affected range stops below 66, so it looks safe — our inference, not a vendor statement
Affected range stops below 66.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (4)

x_refsource_MISCIssue TrackingVendor Advisory
Source: [email protected]
https://bugzilla.mozilla.org/show_bug.cgi?id=1437009
x_refsource_MISCIssue TrackingPermissions RequiredVendor Advisory
Source: [email protected]
https://bugzilla.mozilla.org/show_bug.cgi?id=1515863
x_refsource_MISCThird Party Advisory
Source: [email protected]
https://w3c.github.io/webappsec-upgrade-insecure-requests/
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2019-07/

CVSS

5.8MEDIUM[email protected]
Confidentiality
PARTIAL
Integrity
PARTIAL
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-346

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