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

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-01 · updated 2026-10-05
Weakness: CWE-476

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.

Affected products

Apache HTTP Server: from 2.4.0 before 2.4.69 — fixed in 2.4.69

How to fix

Upgrade to a fixed version: Apache HTTP Server 2.4.69. Check the vendor advisory for mitigations.

References

https://httpd.apache.org/security/vulnerabilities_24.html
http://www.openwall.com/lists/oss-security/2026/10/01/25

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