---
title: "Apache HTTP/2 RCE: Detecting the mod_http2 Flaw Behind CVE-2026-119618"
url: "https://www.armorcode.com/blog/apache-http2-rce-cve-2026-119618"
markdown_url: "https://www.armorcode.com/blog/apache-http2-rce-cve-2026-119618.md"
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primary_entity: "Apache HTTP/2 RCE: Detecting the mod_http2 Flaw Behind CVE-2026-119618"
citation_value: "Published on ArmorCode; canonical URL https://www.armorcode.com/blog/apache-http2-rce-cve-2026-119618."
last_updated: "2026-11-12T22:06:41-08:00"
---
Apache HTTP/2 RCE: Detecting the mod_http2 Flaw Behind CVE-2026-119618
Key Takeaways
- **What it is:** The Apache HTTP/2 RCE, CVE-2026-119618, is a critical race condition in mod_http2’s assign_headers() that Apache says can lead to remote code execution (RCE).
- **Who is affected:** Apache HTTP Server 2.4.55 through 2.4.70 and standalone mod_h2 2.0.8 through 2.0.42. Prioritize internet-facing hosts that serve HTTP/2.
- **How to fix it:** Upgrade to 2.4.71 or your distribution’s patched package, then restart Apache. Version 2.4.71 also fixes two other CVEs, in mod_md and mod_vhost_alias.
- **Interim mitigation:** If you cannot patch, disable HTTP/2 with Protocols http/1.1 .
- **How to find your exposure:** Search by CVE ID in ArmorCode with Anya or the “Apache-mod_http2-RCE 2026” view. Backported packages and per-host configuration make version-only queries unreliable.
What is the Apache HTTP/2 RCE (CVE-2026-119618)?
Apache HTTP/2 RCE is the shorthand for CVE-2026-119618, a critical race condition in Apache HTTP Server’s mod_http2 that Apache says can lead to remote code execution (RCE). On November 11, 2026, the Apache HTTP Server project released version **2.4.71** to fix three vulnerabilities. The most serious is **CVE-2026-119618**, a flaw in mod_http2 that Apache rates **critical** and describes as being able to lead to remote code execution (RCE). Vendors describe it as exploitable by a remote, unauthenticated attacker. The flaw is credited to Anthropic (ANT-2026-MAPKT6MZ) and Google Cloud’s Vulnerability Research team, and Apache received the report on October 26.
Apache HTTP Server is among the most widely deployed web servers, and it often ships inside other products. That makes the first task finding every instance, including the ones you did not know were Apache.
How the Apache HTTP/2 RCE works in mod_http2
The bug is in the assign_headers() function of the HTTP/2 module (mod_http2). It is a race condition: concurrent threads use a shared resource without proper synchronization, which can corrupt heap memory. An attacker who controls the timing can turn that memory corruption into code execution with the privileges of the web server process.
Only deployments that serve HTTP/2 are exposed. In practice that means mod_http2 is loaded and the h2 or h2c protocols are enabled.
Which Apache versions are affected by the HTTP/2 RCE?
| **Product** | **Affected** | **Fixed** |
| --- | --- | --- |
| Apache HTTP Server | 2.4.55 through 2.4.70 | 2.4.71 and newer |
| Standalone mod_h2 (GitHub) | 2.0.8 through 2.0.42 | A release newer than 2.0.42 |
Hunt by CVE ID, not by version alone
A query such as “httpd version between 2.4.55 and 2.4.70” will mislead you in both directions.
- **False positives.** Linux distributions backport fixes into their own httpd and apache2 packages without moving to upstream 2.4.71, so a patched host can still show an older version string.
- **Configuration matters.** A host with mod_http2 not loaded, or with HTTP/2 disabled, is not exposed even on a vulnerable version. Version strings cannot tell you that.
- **False negatives.** Apache is bundled in appliances, control panels and container images, often with no obvious component name.
Map findings by **CVE-2026-119618**, and use version and configuration only to prioritize, for example putting internet-facing hosts with HTTP/2 enabled first.
How to detect the Apache HTTP/2 RCE in your environment with ArmorCode
1. Ask Anya
Start with Anya, ArmorCode’s AI security champion, where you can ask targeted questions such as:
- Am I impacted by CVE-2026-119618?
- Show me all applications, services, and workloads exposed to CVE-2026-119618.
- Am I vulnerable to the Apache HTTP/2 RCE vulnerability (CVE-2026-119618)?
2. Findings Page
- Navigate to the Findings page to access the pre-configured saved view, “Apache-mod_http2-RCE 2026”. By consolidating results around the CVE ID, it unifies findings from all connected scanners into a single triage workflow. Prioritize remediation by sorting assets according to their criticality and internet exposure.
How to fix the Apache HTTP/2 RCE
1. **Upgrade to 2.4.71 or later,** or to your distribution’s patched package. For vendor packages, check the changelog for the CVE ID, not the version number. Restart or gracefully reload Apache so the new binary and modules load.
2. **Update standalone mod_h2** if you build it separately from GitHub, and verify the deployed module version.
3. **If you cannot patch, disable HTTP/2.** Set Protocols http/1.1 in your configuration, removing h2 and h2c, and reload. Apache has published no official workaround, so treat this as a temporary measure from Wiz and verify with apachectl -M | grep -i http2 and a test request.
4. **Check which hosts serve HTTP/2.** Look for LoadModule http2_module and Protocols directives in your configuration, and prioritize internet-facing servers.
5. **Watch for compromise.** No indicators have been published. Likely signals, inferred from the bug type, are httpd or apache2 workers spawning shells or download tools, and repeated worker crashes (segfaults) in the error log. If you cannot rule out exploitation, isolate the host and preserve logs.
References
- **Apache:** [Apache HTTP Server 2.4 vulnerabilities](https://httpd.apache.org/security/vulnerabilities_24.html)
- **TheHackerWire:** [Apache HTTP Server 2.4.71 Fixes Critical mod_http2 Heap Corruption](https://www.thehackerwire.com/critical-alert-cve-2026-119618-exposes-apache-http-2-servers-to-remote-code-execution/)