CVE-2018-12403
CVE-2018-12403 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: Medium (CVSS 3.x base score 5.3)
- CVSS v2: 5.0
- EPSS exploit prediction: 2% (77th percentile)
- Actively exploited: Not listed in CISA KEV
- Affected product: Mozilla Firefox
- Published:
- Last modified:
Description
If a site is loaded over a HTTPS connection but loads a favicon resource over HTTP, the mixed content warning is not displayed to users. This vulnerability affects Firefox < 63.
Frequently asked questions
- What is CVE-2018-12403?
- If a site is loaded over a HTTPS connection but loads a favicon resource over HTTP, the mixed content warning is not displayed to users. This vulnerability affects Firefox < 63.
- How severe is CVE-2018-12403?
- CVE-2018-12403 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
- Is CVE-2018-12403 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2018-12403?
- CVE-2018-12403 primarily affects Mozilla Firefox. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2018-12403?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2018-12403 published?
- CVE-2018-12403 was published on 2019-02-28 and last updated on 2026-06-17.
References
- http://www.securityfocus.com/bid/105721
- http://www.securitytracker.com/id/1041944
- https://bugzilla.mozilla.org/show_bug.cgi?id=1484753
- https://usn.ubuntu.com/3801-1/
- https://www.mozilla.org/security/advisories/mfsa2018-26/
Affected products (5)
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
More vulnerabilities in Mozilla Firefox
- CVE-2026-4725 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149…
- CVE-2026-4692 — Critical (CVSS 10.0): Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Firefox ESR…
- CVE-2026-4689 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was…
- CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
- CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
- CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…