Integer overflow in the scan_cidfont function in X.Org 6.8.2 and XFree86 X server allows local users to execute arbitrary code via crafted (1) CMap and (2) CIDFont font data with modified item counts in the (a) begincodespacerange, (b) cidrange, and (c) notdefrange sections.
Conclusion & alert: CVE-2006-3740 is rated Moderate Risk (42.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.50%). 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 | 2026-06-15 | 0.09% | 0.50% | +0.41% |
| 2 | 2023-11-08 | 0.05% | 0.09% | +0.05% |
| 3 | 2023-03-07 | — | 0.05% | — |
Full EPSS history (4 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.2 | 2.0 | HIGH |
|
3.9 | 10.0 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2006-3740 not yet assigned priority: Debian including 1 source packages (libxfont), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2006-3740 |
gentoo
|
high | CVE-2006-3740: 1 GLSA(s) (200609-07), 2 atom(s) (x11-base/xorg-x11, x11-libs/libXfont); latest impact high. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2006-3740 |
redhat
|
high | — | https://access.redhat.com/security/cve/CVE-2006-3740 |
ubuntu
|
medium | CVE-2006-3740 medium priority: Ubuntu including 2 source packages (libxfont, xorg), 8 status rows across 4 suites (dapper, edgy, feisty, upstream): not-affected 4, released 3, needs-triage 1. | https://ubuntu.com/security/CVE-2006-3740 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| x.org | x.org | 6.8.2 | cpe:2.3:a:x.org:x.org:6.8.2:*:*:*:*:*:*:* |
| xfree86_project | xfree86_x | — | cpe:2.3:a:xfree86_project:xfree86_x:*:*:*:*:*:*:*:* |