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 JSAPI access to the GetProperty function, which allows remote attackers to bypass the Same Origin Policy and possibly have unspecified other impact via a crafted web site.
Conclusion & alert: CVE-2012-3991 is rated Moderate Risk (64.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.42%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2025-09-26 | 1.92% | 1.42% | -0.50% |
| 2 | 2025-04-13 | 1.38% | 1.92% | +0.54% |
| 3 | 2025-03-30 | — | 1.38% | — |
Full EPSS history (11 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.3 | 2.0 | HIGH |
|
8.6 | 10.0 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
gentoo
|
high | CVE-2012-3991: 1 GLSA(s) (201301-01), 14 atom(s) (dev-libs/nss, mail-client/mozilla-thunderbird, …); latest impact high. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2012-3991 |
redhat
|
critical | — | https://access.redhat.com/security/cve/CVE-2012-3991 |
suse
|
medium | CVE-2012-3991 severity moderate: SUSE including 71 source package names (MozillaFirefox, MozillaFirefox-10.0.9-0.3.1, …), 122 product×package rows across 43 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (43 product lines)): Fixed 91, Known Not Affected 31. | https://www.suse.com/security/cve/CVE-2012-3991/ |
ubuntu
|
high | CVE-2012-3991 high priority: Ubuntu including 4 source packages (firefox, seamonkey, thunderbird, xulrunner-1.9.2), 36 status rows across 9 suites (hardy, lucid, natty, oneiric, precise, quantal, raring, saucy, upstream): released 17, DNE 9, ignored 9, needs-triage 1. | https://ubuntu.com/security/CVE-2012-3991 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| mozilla | firefox | < 10.0.8 | cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* |
| mozilla | thunderbird_esr | < 10.0.8 | cpe:2.3:a:mozilla:thunderbird_esr:*:*:*:*:*:*:*:* |
| mozilla | firefox | < 16.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* |
| mozilla | thunderbird | < 16.0 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* |
| mozilla | seamonkey | < 2.13 | cpe:2.3:a:mozilla:seamonkey:*:*:*:*:*:*:*:* |
| canonical | ubuntu_linux | 10.04 | cpe:2.3:o:canonical:ubuntu_linux:10.04:*:*:*:-:*:*:* |
| canonical | ubuntu_linux | 11.04 | cpe:2.3:o:canonical:ubuntu_linux:11.04:*:*:*:*:*:*:* |
| canonical | ubuntu_linux | 11.10 | cpe:2.3:o:canonical:ubuntu_linux:11.10:*:*:*:*:*:*:* |
| canonical | ubuntu_linux | 12.04 | cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:* |
| redhat | enterprise_linux_desktop | 5.0 | cpe:2.3:o:redhat:enterprise_linux_desktop:5.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_desktop | 6.0 | cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_eus | 6.3 | cpe:2.3:o:redhat:enterprise_linux_eus:6.3:*:*:*:*:*:*:* |
| redhat | enterprise_linux_server | 5.0 | cpe:2.3:o:redhat:enterprise_linux_server:5.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_server | 6.0 | cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_workstation | 5.0 | cpe:2.3:o:redhat:enterprise_linux_workstation:5.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_workstation | 6.0 | cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:* |
| suse | linux_enterprise_desktop | 10 | cpe:2.3:o:suse:linux_enterprise_desktop:10:sp4:*:*:*:*:*:* |
| suse | linux_enterprise_desktop | 11 | cpe:2.3:o:suse:linux_enterprise_desktop:11:sp3:*:*:*:*:*:* |
| suse | linux_enterprise_sdk | 10 | cpe:2.3:o:suse:linux_enterprise_sdk:10:sp4:*:*:*:*:*:* |
| suse | linux_enterprise_server | 10 | cpe:2.3:o:suse:linux_enterprise_server:10:sp4:*:*:*:*:*:* |
| suse | linux_enterprise_server | 11 | cpe:2.3:o:suse:linux_enterprise_server:11:sp3:*:*:*:*:*:* |
| suse | linux_enterprise_server | 11 | cpe:2.3:o:suse:linux_enterprise_server:11:sp3:*:*:*:vmware:*:* |