Concurrency vulnerability in Mozilla Firefox 1.5.0.6 and earlier allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via multiple Javascript timed events that load a deeply nested XML file, followed by redirecting the browser to another page, which leads to a concurrency failure that causes structures to be freed incorrectly, as demonstrated by (1) ffoxdie and (2) ffoxdie3. NOTE: it has been reported that Netscape 8.1 and K-Meleon 1.0.1 are also affected by ffoxdie. Mozilla confirmed to CVE that ffoxdie and ffoxdie3 trigger the same underlying vulnerability. NOTE: it was later reported that Firefox 2.0 RC2 and 1.5.0.7 are also affected.
Conclusion & alert: CVE-2006-4253 is rated High Exploit Risk (77.2/100): CVSS High severity, with high exploitation likelihood (EPSS 30.76%, 97th percentile). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| 28380 | exploit_db | edb | 2006-08-12 | Exploit-DB ↗ |
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 | 2026-01-01 | 32.81% | 30.76% | -2.05% |
| 2 | 2025-07-24 | 32.26% | 32.81% | +0.55% |
| 3 | 2025-06-01 | — | 32.26% | — |
Full EPSS history (18 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.6 | 2.0 | HIGH |
|
4.9 | 10.0 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2006-4253: no source package rows; 0 state rows across 0 repos (none); fixed 0, open 0. | https://security.alpinelinux.org/vuln/CVE-2006-4253 |
debian
|
medium | CVE-2006-4253 medium priority: Debian including 2 source packages (firefox, thunderbird), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. | https://security-tracker.debian.org/tracker/CVE-2006-4253 |
gentoo
|
normal | CVE-2006-4253: 3 GLSA(s) (200609-19, 200610-01, 200610-04), 5 atom(s) (mail-client/mozilla-thunderbird, mail-client/mozilla-thunderbird-bin, www-client/mozilla-firefox, www-client/mozilla-firefox-bin, www-client/seamonkey); latest impact normal. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2006-4253 |
redhat
|
high | — | https://access.redhat.com/security/cve/CVE-2006-4253 |
suse
|
medium | — | https://www.suse.com/security/cve/CVE-2006-4253/ |
ubuntu
|
medium | CVE-2006-4253 medium priority: Ubuntu including 6 source packages (firefox, firefox-3.0, lightning-sunbird, midbrowser, mozilla-thunderbird, xulrunner), 30 status rows across 5 suites (dapper, edgy, feisty, gutsy, upstream): DNE 11, released 9, needs-triage 6, not-affected 3, ignored 1. | https://ubuntu.com/security/CVE-2006-4253 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| k-meleon_project | k-meleon | 1.0.1 | cpe:2.3:a:k-meleon_project:k-meleon:1.0.1:*:*:*:*:*:*:* |
| mozilla | firefox | 0.8 | cpe:2.3:a:mozilla:firefox:0.8:*:*:*:*:*:*:* |
| mozilla | firefox | 0.9 | cpe:2.3:a:mozilla:firefox:0.9:*:*:*:*:*:*:* |
| mozilla | firefox | 0.9 | cpe:2.3:a:mozilla:firefox:0.9:rc:*:*:*:*:*:* |
| mozilla | firefox | 0.9.1 | cpe:2.3:a:mozilla:firefox:0.9.1:*:*:*:*:*:*:* |
| mozilla | firefox | 0.9.2 | cpe:2.3:a:mozilla:firefox:0.9.2:*:*:*:*:*:*:* |
| mozilla | firefox | 0.9.3 | cpe:2.3:a:mozilla:firefox:0.9.3:*:*:*:*:*:*:* |
| mozilla | firefox | 0.10 | cpe:2.3:a:mozilla:firefox:0.10:*:*:*:*:*:*:* |
| mozilla | firefox | 0.10.1 | cpe:2.3:a:mozilla:firefox:0.10.1:*:*:*:*:*:*:* |
| mozilla | firefox | 1.0 | cpe:2.3:a:mozilla:firefox:1.0:*:*:*:*:*:*:* |
| mozilla | firefox | 1.0.1 | cpe:2.3:a:mozilla:firefox:1.0.1:*:*:*:*:*:*:* |
| mozilla | firefox | 1.0.2 | cpe:2.3:a:mozilla:firefox:1.0.2:*:*:*:*:*:*:* |
| mozilla | firefox | 1.0.3 | cpe:2.3:a:mozilla:firefox:1.0.3:*:*:*:*:*:*:* |
| mozilla | firefox | 1.0.4 | cpe:2.3:a:mozilla:firefox:1.0.4:*:*:*:*:*:*:* |
| mozilla | firefox | 1.0.5 | cpe:2.3:a:mozilla:firefox:1.0.5:*:*:*:*:*:*:* |
| mozilla | firefox | 1.0.6 | cpe:2.3:a:mozilla:firefox:1.0.6:*:*:*:*:*:*:* |
| mozilla | firefox | 1.0.7 | cpe:2.3:a:mozilla:firefox:1.0.7:*:*:*:*:*:*:* |
| mozilla | firefox | 1.0.8 | cpe:2.3:a:mozilla:firefox:1.0.8:*:*:*:*:*:*:* |
| mozilla | firefox | 1.5 | cpe:2.3:a:mozilla:firefox:1.5:*:*:*:*:*:*:* |
| mozilla | firefox | 1.5 | cpe:2.3:a:mozilla:firefox:1.5:beta1:*:*:*:*:*:* |
| mozilla | firefox | 1.5 | cpe:2.3:a:mozilla:firefox:1.5:beta2:*:*:*:*:*:* |
| mozilla | firefox | 1.5.0.1 | cpe:2.3:a:mozilla:firefox:1.5.0.1:*:*:*:*:*:*:* |
| mozilla | firefox | 1.5.0.2 | cpe:2.3:a:mozilla:firefox:1.5.0.2:*:*:*:*:*:*:* |
| mozilla | firefox | 1.5.0.3 | cpe:2.3:a:mozilla:firefox:1.5.0.3:*:*:*:*:*:*:* |
| mozilla | firefox | 1.5.0.4 | cpe:2.3:a:mozilla:firefox:1.5.0.4:*:*:*:*:*:*:* |
| mozilla | firefox | 1.5.0.5 | cpe:2.3:a:mozilla:firefox:1.5.0.5:*:*:*:*:*:*:* |
| mozilla | firefox | 1.5.0.6 | cpe:2.3:a:mozilla:firefox:1.5.0.6:*:*:*:*:*:*:* |
| netscape | navigator | 8.1 | cpe:2.3:a:netscape:navigator:8.1:*:*:*:*:*:*:* |