CVE-2026-63686 Apache HTTP Server: mod_xml2enc crash on charset conversion failure

What is CVE-2026-63686?

CVE-2026-63686 is a high-severity vulnerability in Apache Http Server, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A NULL pointer dereference in mod_xml2enc in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an untrusted backend server to cause a denial of service via a proxied response with a charset whose conversion partially succeeds then fails.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.

Weakness: CWE-476

Which versions are affected by CVE-2026-63686?

1 open source package ship an affected version, including apache. It affects 1 product.

Products include Apache Http Server.

How do I fix CVE-2026-63686?

Upgrade apache to 2.4.69 or later.

Is CVE-2026-63686 being exploited?

There is no known exploitation of CVE-2026-63686 in the wild and no public exploit code.

Other vulnerabilities in Apache Http Server

• CVE-2021-42013 Apache HTTP Server Path Traversal Exploited Critical 9.8
• CVE-2024-38475 Apache HTTP Server Improper Escaping of Output Exploited Critical 9.1
• CVE-2021-40438 Apache HTTP Server-Side Request Forgery (SSRF) Exploited Critical 9.0
• CVE-2019-0211 Apache HTTP Server Privilege Escalation Exploited High 7.8
• CVE-2021-41773 Apache HTTP Server Path Traversal Exploited High 7.5

All Apache Http Server vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2026-63686, AZL-106755, BELL-CVE-2026-63686, BIT-apache-2026-63686, CLSA-2026-1791488147, CLSA-2026-1791552137 and 10 more.