Format string vulnerability in mod_gzip_printf for mod_gzip 1.3.26.1a and earlier, and possibly later official versions, when running in debug mode and using the Apache log, allows remote attackers to execute arbitrary code via format string characters in an HTTP GET request with an "Accept-Encoding: gzip" header.
Conclusion & alert: CVE-2003-0843 is rated Moderate Risk (58.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.27%). 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 | 1.73% | 2.27% | +0.53% |
| 2 | 2025-03-30 | 3.26% | 1.73% | -1.52% |
| 3 | 2025-03-29 | — | 3.26% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 2.0 | HIGH |
|
10.0 | 6.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| dag_apt_repository | mod_gzip | <= 1.3.26.1a | cpe:2.3:a:dag_apt_repository:mod_gzip:*:*:*:*:*:*:*:* |