CVE-2026-43951

Apache HTTP Server: OOB Read in `merge_response_headers` can cause crash

MEDIUM
6.5
CVSS Score
Published: June 8, 2026 at 03:16 PM UTC
Updated: July 23, 2026 at 07:35 AM UTC
1 product affected across 1 vendorHTTP Server

Using Apache HTTP Server by Apache Software Foundation?

Get instant alerts when new vulnerabilities affect Apache HTTP Server - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM6.5
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

Out-of-bounds Read vulnerability in Apache HTTP Server with mod_headers and mod_mime and multiple response languages. This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.4.0 ≤ v ≤ 2.4.672.4.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2026/06/08/10

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-125

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card