How severe is CVE-2012-3986?

CVE-2012-3986 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2012-3986 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2012-3986?

CVE-2012-3986 primarily affects Mozilla Firefox. In total, 22 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2012-3986?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2012-3986 published?

CVE-2012-3986 was published on 2012-10-10 and last updated on 2026-06-16.

CVE-2012-3986

CVE-2012-3986 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Mozilla Firefox
Published: 2012-10-10
Last modified: 2026-06-16

Description

Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbird before 16.0, Thunderbird ESR 10.x before 10.0.8, and SeaMonkey before 2.13 do not properly restrict calls to DOMWindowUtils (aka nsDOMWindowUtils) methods, which allows remote attackers to bypass intended access restrictions via crafted JavaScript code.

Frequently asked questions

What is CVE-2012-3986?: Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbird before 16.0, Thunderbird ESR 10.x before 10.0.8, and SeaMonkey before 2.13 do not properly restrict calls to DOMWindowUtils (aka nsDOMWindowUtils) methods, which allows remote attackers to bypass intended access restrictions via crafted JavaScript code.
How severe is CVE-2012-3986?: CVE-2012-3986 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2012-3986 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2012-3986?: CVE-2012-3986 primarily affects Mozilla Firefox. In total, 22 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2012-3986?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2012-3986 published?: CVE-2012-3986 was published on 2012-10-10 and last updated on 2026-06-16.

References

Affected products (22)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird_esr:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:seamonkey:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:10.04:*:*:*:-:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:11.04:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:11.10:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
cpe:2.3:o:redhat:enterprise_linux_desktop:5.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_eus:6.3:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server:5.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_workstation:5.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:6.0:*:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_desktop:10:sp4:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_desktop:11:sp3:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_sdk:10:sp4:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_server:10:sp4:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_server:11:sp3:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_server:11:sp3:*:*:*:vmware:*:*

More vulnerabilities in Mozilla Firefox

CVE-2026-75874 — Critical (CVSS 10.0): Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154 and Thunderbird 154.
CVE-2026-16367 — Critical (CVSS 10.0): Sandbox escape due to invalid pointer in the Disability Access APIs component. This vulnerability was fixed in 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…

All CVEs affecting Mozilla Firefox →

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48056 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download video content. Versions prior to 2.5.0…
CVE-2026-33267 — Critical (CVSS 10.0): Improper Input Validation vulnerability in Apache Traffic Server. This issue affects Apache Traffic Server: from 9.2.0…
CVE-2026-47668 — Critical (CVSS 10.0): DbGate is cross-platform database manager. In versions 7.1.8 and prior, DbGate's JSON script runner (`POST…
CVE-2026-16117 — Critical (CVSS 10.0): Impact: @fastify/http-proxy versions up to and including 11.5.0 fail to rewrite the request prefix when the prefix…
CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →