A crafted method sent through HTTP/2 will bypass validation and be forwarded by mod_proxy, which can lead to request splitting or cache poisoning. This issue affects Apache HTTP Server 2.4.17 to 2.4.48.
Loading...
Loading...
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 7.5; sources differ by 0.0.
A crafted method sent through HTTP/2 will bypass validation and be forwarded by mod_proxy, which can lead to request splitting or cache poisoning. This issue affects Apache HTTP Server 2.4.17 to 2.4.48.
August 16, 2021
May 1, 2025
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | apache2-bin (2.4.46-4ubuntu1.2) @ hirsute | 2026-05-26 | ubuntu |
| redhat | httpd | 2022-10-26 | redhat |
| redhat | jbcs-httpd24-httpd-0:2.4.51-28.el7jbcs | 2022-10-26 | redhat |
| redhat | httpd24-httpd-0:2.4.34-23.el7.5 | 2022-09-29 | redhat |
| redhat | httpd:2.4-8060020220321163517.d63f516d | 2022-05-10 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
Request splitting via HTTP/2 method injection and mod_proxy
RHSA-2022:1915 — Moderate
RHSA-2022:6753 — Moderate
RHSA-2022:7143 — Moderate
RHSA-2022:7144 — Moderate
Apache HTTP Server vulnerabilities
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-33193
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.