Apache HTTP Server vulnerabilities: known CVEs & security history
Apache · Web / Runtime · 18 tracked CVEs · 1 actively exploited · updated August 2026 · what is a CVE? →
This is the full list of known vulnerabilities (CVEs) across all Apache HTTP Server release lines — 18 in total, with 1 actively exploited in the wild. A CVE here doesn't mean your version is affected — check Apache HTTP Server's current status and the safe version to run.
Known Apache HTTP Server CVEs
Actively-exploited and most-severe first. Open any CVE for full details.
| CVE | Severity | CVSS | EPSS | Year |
|---|---|---|---|---|
| CVE-2021-40438⚡ exploited | critical | 9 | 100% | 2021 |
| CVE-2026-44631 | critical | 9.8 | 0% | 2026 |
| CVE-2026-29167 | critical | 9.8 | 1% | 2026 |
| CVE-2026-28780 | critical | 9.8 | 1% | 2026 |
| CVE-2026-42535 | critical | 9.1 | 1% | 2026 |
| CVE-2026-23918 | high | 8.8 | 46% | 2026 |
| CVE-2026-49975 | high | 7.5 | 17% | 2026 |
| CVE-2026-42536 | high | 7.5 | 1% | 2026 |
| CVE-2026-34356 | high | 7.5 | 1% | 2026 |
| CVE-2026-34355 | high | 7.5 | 1% | 2026 |
| CVE-2025-3891 | high | 7.5 | 1% | 2025 |
| CVE-2026-48913 | high | 7.3 | 0% | 2026 |
| CVE-2026-44186 | high | 7.3 | 1% | 2026 |
| CVE-2026-44185 | high | 7.3 | 1% | 2026 |
| CVE-2026-43951 | medium | 6.5 | 1% | 2026 |
| CVE-2026-29170 | medium | 6.1 | 1% | 2026 |
| CVE-2026-44119 | medium | 5.5 | 0% | 2026 |
| CVE-2009-3720 | medium | 5 | 28% | 2009 |
Is my Apache HTTP Server version affected?
The list above spans every release. To know whether your version is affected — and the minimum safe version to upgrade to — check it directly.
Check your Apache HTTP Server version → · Monitor Apache HTTP Server for new CVEs →
Apache HTTP Server vulnerabilities — frequently asked
How many known vulnerabilities does Apache HTTP Server have?
IsItPatched tracks 18 CVEs for Apache HTTP Server, 1 of which is actively exploited (CISA KEV). 5 are critical-severity and 9 high-severity. These span every release line — what matters is whether the version you run is affected.
Does Apache HTTP Server have any actively-exploited vulnerabilities?
Yes — 1 Apache HTTP Server CVE is in CISA's Known Exploited Vulnerabilities catalog, meaning it is confirmed exploited in the wild (1 linked to ransomware). Patch it as a priority.
What is the most severe Apache HTTP Server vulnerability?
Among tracked issues, CVE-2021-40438 (CRITICAL, CVSS 9), which is actively exploited, ranks highest — a Server-side request forgery (SSRF) weakness.
Is Apache HTTP Server safe to use?
It depends on the version. The latest supported Apache HTTP Server release (2.4.68) clears the known issues; older versions may still be affected. Check the exact version you run for a verdict.
CVE data aggregated from NVD, CISA KEV and EPSS (FIRST.org). Related: Apache HTTP Server security status · Apache HTTP Server end-of-life · actively-exploited CVEs. Always verify against Apache's advisories — see our disclaimer.