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
Published Apr 26, 2019
7.4
HIGHCVSS 3.0
EPSS 0.56%
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 products
-
- Version unspecifiedStatusaffectedConstraints<66
- Version
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
AV:N/AC:M/Au:N/C:P/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Table of values (12 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.56% (0.00559) | 44.49th | v5 (v2026.06.15) |
| Sep 20, 2026 | 0.56% (0.00559) | 45.32th | v5 (v2026.06.15) |
| Jul 20, 2024 | 0.15% (0.00155) | 52.28th | v3 (v2023.03.01) |
| Apr 19, 2024 | 0.15% (0.00155) | 51.40th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.11% (0.00107) | 41.84th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.02% (0.01018) | 40.69th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.02% (0.01018) | 36.86th | v2 (v2022.01.01) |
| Feb 4, 2022 | 15.35% (0.15351) | 91.59th | v2 (v2022.01.01) |
| Feb 3, 2022 | 4.50% (0.04504) | 76.47th | v1 |
| Jan 6, 2022 | 4.50% (0.04504) | 76.26th | v1 |
| Jan 5, 2022 | 1.04% (0.01040) | 65.70th | v5 (v2026.06.15) |
| Apr 14, 2021 | 1.04% (0.01040) | 0.00th | v1 |
References (4)
- https://bugzilla.mozilla.org/show_bug.cgi?id=1437009 x_refsource_MISCIssue TrackingVendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1515863 x_refsource_MISCIssue TrackingPermissions RequiredVendor Advisory
- https://w3c.github.io/webappsec-upgrade-insecure-requests/ x_refsource_MISCThird Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-07/ x_refsource_MISCVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=1437009 | x_refsource_MISCIssue TrackingVendor Advisory | |
| https://bugzilla.mozilla.org/show_bug.cgi?id=1515863 | x_refsource_MISCIssue TrackingPermissions RequiredVendor Advisory | |
| https://w3c.github.io/webappsec-upgrade-insecure-requests/ | x_refsource_MISCThird Party Advisory | |
| https://www.mozilla.org/security/advisories/mfsa2019-07/ | x_refsource_MISCVendor Advisory |
Change history (0)
No recorded changes yet.