MEDIUM

CVE-2026-43951

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

CVSS v3

6.5

MEDIUM

EPSS Score

1.0 %

exploit probability, as of 2026-10-04

CISA KEV

known exploited

Exploitation

none

SSVC status

Description

Microsoft Security Update (CVE-2026-43951)

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Published: 2026-06-19
MSRC Title: Apache HTTP Server: OOB Read in `merge_response_headers` can cause crash

Frequently asked questions

What is CVE-2026-43951?

Microsoft Security Update (CVE-2026-43951)

Is CVE-2026-43951 actively exploited?

Active exploitation of CVE-2026-43951 has not been confirmed. Its EPSS score was 1.0% on 2026-10-04, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-43951?

CVE-2026-43951 has a CVSS v3 base score of 6.5 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Is CVE-2026-43951 affecting your environment?

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