CVE-2026-63686

Publication date 1 October 2026

Last updated 11 November 2026

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
apache2	26.10 stonking	Fixed in 2.4.68-1ubuntu6.1
	26.04 LTS resolute	Fixed in 2.4.66-2ubuntu2.6
	24.04 LTS noble	Fixed in 2.4.58-1ubuntu8.17
	22.04 LTS jammy	Fixed in 2.4.52-1ubuntu4.25
	20.04 LTS focal	Fixed in 2.4.41-4ubuntu3.23+esm9
	18.04 LTS bionic	Fixed in 2.4.29-1ubuntu4.27+esm13
	16.04 LTS xenial	Fixed in 2.4.18-2ubuntu3.17+esm22
	14.04 LTS trusty	Fixed in 2.4.7-1ubuntu4.22+esm17

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
apache2	Upstream: 6fa059e

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	None
Availability impact	High

Scores

Parameter	Value
Base score	7.5 · High
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-8931-1
Apache HTTP Server vulnerabilities
14 October 2026

USN-9016-1
Apache HTTP Server vulnerabilities
10 November 2026