Multiple buffer overflows in squidGuard 1.4 allow remote attackers to bypass intended URL blocking via a long URL, related to (1) the relationship between a certain buffer size in squidGuard and a certain buffer size in Squid and (2) a redirect URL that contains information about the originally requested URL.
Conclusion & alert: CVE-2009-3826 is rated Moderate Risk (46.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.71%). 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 | 2025-03-30 | 3.67% | 1.71% | -1.96% |
| 2 | 2025-03-29 | 1.71% | 3.67% | +1.96% |
| 3 | 2025-03-17 | — | 1.71% | — |
Full EPSS history (8 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
low | CVE-2009-3826 low priority: Debian including 1 source packages (squidguard), 4 status rows across 4 suites (bookworm, bullseye, sid, trixie): resolved 4. | https://security-tracker.debian.org/tracker/CVE-2009-3826 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2009-3826 |
ubuntu
|
medium | CVE-2009-3826 medium priority: Ubuntu including 1 source packages (squidguard), 7 status rows across 7 suites (dapper, hardy, intrepid, jaunty, karmic, lucid, upstream): released 6, ignored 1. | https://ubuntu.com/security/CVE-2009-3826 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| squidguard | squidguard | 1.4 | cpe:2.3:a:squidguard:squidguard:1.4:*:*:*:*:*:*:* |