CVE-2026-56153

A flaw was found in httpd's mod_charset_lite module. A heap-based buffer overflow (an out-of-bounds memory write) occurs in the finish_partial_char function when handling character set conversions. A remote attacker can exploit this flaw by sending specially crafted requests, leading to memory corruption. This issue primarily results in a Denial of Service (DoS) condition by crashing the server process.

This vulnerability is rated as having an Important impact for Red Hat products because an unauthenticated remote attacker can trigger memory corruption across the network, resulting in worker termination and service denial. The flaw specifically targets environments where character set translation features are enabled within the web server. Deployments that do not actively load or configure the mod_charset_lite module are not susceptible to this attack vector.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Disable the mod_charset_lite module if character set translation is not required.

1. Locate the configuration file loading the module, typically within /etc/httpd/conf.modules.d/ (such as 00-base.conf or a dedicated module configuration file).
2. Comment out or remove the LoadModule charset_lite_module line:

# LoadModule charset_lite_module modules/mod_charset_lite.so

3. Reload the httpd service to apply the configuration change:

systemctl reload httpd

Caveats: Applications that depend on mod_charset_lite for on-the-fly character set conversion will fail to translate character sets once the module is disabled.

Warning: Reloading or restarting the httpd service will momentarily disrupt active network connections or in-flight requests.