Vulnerability

CVE-2026-43951

Medium· 6.5CVSS6.5EPSS0%

.rules3/5

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.

Threat signal

65/100

Elevated

Severity

medium

CVSS

6.5

EPSS

Active

CVSS

v3.1via NVDOpen in FIRST calculator →

6.5/ 10MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Attack VectorNetworkExploitable remotely over the internet — no local access needed.
Attack ComplexityLowNo special conditions — exploit works reliably.
Privileges RequiredNoneUnauthenticated — no credentials needed.
User InteractionNoneFully automated — no victim action needed.
ScopeUnchangedImpact contained to the vulnerable component.
Confidentiality ImpactLowSome data disclosure; attacker doesn't fully control what.
Integrity ImpactLowSome data modification; attacker doesn't fully control extent.
Availability ImpactNoneNo availability impact.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

0.13%

probability of exploitation in next 30 days

p32

higher than 32% of all CVEs

3-day trend↑ 0.1pp

Low exploitation likelihood — defer if no other signals fire.

Vendor VEX

No VEX statements published for CVE-2026-43951. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCDefer

No exploitation, limited impact or prevalence

exploitation: none
automatable: no
impact: partial
mission: support

Lifecycle

2026-06-08Published
2026-06-11Vendor advisory · microsoftCVE-2026-43951 — Apache HTTP Server: OOB Read in `merge_response_headers` can cause crash
2026-06-11Last modified1 source

Entity graph

2 nodes · 1 edges · click to pivot

CVEActorVendor advisoryIOCNews

Vendor advisories

microsoftCVE-2026-43951Apache HTTP Server: OOB Read in `merge_response_headers` can cause crash

References

No source-event history recorded yet. New revisions will appear here as ingestors re-fetch this CVE.