The JavaScript engine in Mozilla Firefox before 1.5.0.10 and 2.x before 2.0.0.2, Thunderbird before 1.5.0.10, and SeaMonkey before 1.0.8 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via certain vectors that trigger memory corruption.
Conclusion & alert: CVE-2007-0777 is rated High Risk (72.1/100): CVSS Critical severity, with high exploitation likelihood (EPSS 42.76%, 97th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize 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 | 2025-10-15 | 41.89% | 42.76% | +0.87% |
| 2 | 2025-03-30 | 51.57% | 41.89% | -9.68% |
| 3 | 2025-03-29 | — | 51.57% | — |
Full EPSS history (17 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
|
normal | CVE-2007-0777: 3 GLSA(s) (200703-04, 200703-08, 200703-18), 6 atom(s) (mail-client/mozilla-thunderbird, mail-client/mozilla-thunderbird-bin, www-client/mozilla-firefox, www-client/mozilla-firefox-bin, www-client/seamonkey, www-client/seamonkey-bin); latest impact normal. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2007-0777 |
redhat
|
critical | — | https://access.redhat.com/security/cve/CVE-2007-0777 |
suse
|
critical | CVE-2007-0777 severity critical: SUSE including 22 source package names (MozillaFirefox-10.0-0.3.2, MozillaFirefox-140.2.0-160000.1.2, …), 22 product×package rows across 7 product lines (SUSE Linux Enterprise Server 11 SP1, SUSE Linux Enterprise Server 11 SP2, … (7 product lines)): Fixed 22. | https://www.suse.com/security/cve/CVE-2007-0777/ |
ubuntu
|
medium | CVE-2007-0777 medium priority: Ubuntu including 6 source packages (firefox, iceape, lightning-sunbird, midbrowser, mozilla-thunderbird, xulrunner), 30 status rows across 5 suites (dapper, edgy, feisty, gutsy, upstream): DNE 11, released 11, needs-triage 6, ignored 1, not-affected 1. | https://ubuntu.com/security/CVE-2007-0777 |
: Successful exploitation in Thunderbird requires that JavaScript be enabled in mail which is not the default setting.
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| mozilla | firefox | >= 1.5, < 1.5.0.10 | cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* |
| mozilla | firefox | >= 2.0, < 2.0.0.2 | cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* |
| mozilla | seamonkey | < 1.0.8 | cpe:2.3:a:mozilla:seamonkey:*:*:*:*:*:*:*:* |
| mozilla | thunderbird | < 1.5.0.10 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* |
| canonical | ubuntu_linux | 5.10 | cpe:2.3:o:canonical:ubuntu_linux:5.10:*:*:*:*:*:*:* |
| canonical | ubuntu_linux | 6.06 | cpe:2.3:o:canonical:ubuntu_linux:6.06:*:*:*:lts:*:*:* |
| canonical | ubuntu_linux | 6.10 | cpe:2.3:o:canonical:ubuntu_linux:6.10:*:*:*:*:*:*:* |