high CVSS 7.5

CVE-2026-46729·Apache vulnerability

NULL Pointer Dereference vulnerability in Apache HTTP Servers mod_heartmonitor over unicast listener. This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.

Severity
high
Software
Apache
Fixed in
2.4.69
Published
2026-10-01

Affected versions

From: 2.4.60

Until: 2.4.69

Fixed in: 2.4.69

How to fix this CVE

Upgrade Apache HTTP Server to version 2.4.69 or later to resolve a null pointer dereference flaw in the mod_heartmonitor module that can cause denial of service. Organizations running versions 2.4.60 through 2.4.68 should prioritize this update, especially if heartbeat monitoring over unicast listeners is enabled in their configuration. After patching, restart the Apache service and verify the new version is running.

sudo dnf update httpd && sudo systemctl restart httpd

Defensia detects this vulnerability

How to check if you are affected

  1. Check the current Apache version: apache2ctl -v (Ubuntu/Debian) or httpd -v (RHEL/CentOS)
  2. Verify if mod_heartmonitor is loaded: grep -i heartmonitor /etc/apache2/mods-enabled/* or grep -i heartmonitor /etc/httpd/conf.modules.d/*
  3. Search Apache error logs for segmentation faults or null pointer errors: grep -i 'segmentation\|null pointer\|heartmonitor' /var/log/apache2/error.log or /var/log/httpd/error_log
  4. Confirm the patch by re-running apache2ctl -v or httpd -v and verifying the version is 2.4.69 or later

FAQ

What is CVE-2026-46729?

CVE-2026-46729 is a null pointer dereference vulnerability in Apache's mod_heartmonitor module that occurs when processing unicast listener traffic, allowing remote attackers to crash the web server and cause a denial of service condition.

Is CVE-2026-46729 being actively exploited?

No, this vulnerability is not currently listed as actively exploited in the CISA Known Exploited Vulnerabilities catalog, and no public proof-of-concept exploits are available.

What versions of Apache are affected by CVE-2026-46729?

Apache HTTP Server versions 2.4.60 through 2.4.68 are vulnerable. Version 2.4.69 and later contain the fix.

How do I check if my server is vulnerable to CVE-2026-46729?

Run 'apache2ctl -v' or 'httpd -v' and check if the version is between 2.4.60 and 2.4.68. If mod_heartmonitor is enabled (check with 'grep heartmonitor /etc/apache2/mods-enabled/*'), your server is at risk.

Does Defensia detect CVE-2026-46729?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Apache is installed on a monitored server, CVE-2026-46729 will appear in your dashboard with remediation steps.

Related Apache CVEs

CVE-2024-38476CVSS 9.8Vulnerability in core of Apache HTTP Server 2.4.59 and earlier are vulnerably to information disclosure, SSRF or local script execution via backend applications whose response headers are malicious or exploitable. Users are recommended to upgrade to version 2.4.60, which fixes this issue.
CVE-2024-38474CVSS 9.8Substitution encoding issue in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows attacker to execute scripts in directories permitted by the configuration but not directly reachable by any URL or source disclosure of scripts meant to only to be executed as CGI. Users are recommended to upgrade to version 2.4.60, which fixes this issue. Some RewriteRules that capture and substitute unsafely will now fail unless rewrite flag "UnsafeAllow3F" is specified.
CVE-2026-28780CVSS 9.8Heap-based Buffer Overflow vulnerability in mod_proxy_ajp of Apache HTTP Server. If mod_proxy_ajp connects to a malicious AJP server this AJP server can send a malicious AJP message back to mod_proxy_ajp and cause it to write 4 attacker controlled bytes after the end of a heap based buffer. This issue affects Apache HTTP Server: through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.
CVE-2025-23048CVSS 9.1In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption. Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.
CVE-2024-38475CVSS 9.1Improper escaping of output in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not intentionally/directly reachable by any URL, resulting in code execution or source code disclosure. Substitutions in server context that use a backreferences or variables as the first segment of the substitution are affected.  Some unsafe RewiteRules will be broken by this change and the rewrite flag "UnsafePrefixStat" can be used to opt back in once ensuring the substitution is appropriately constrained.

References

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