Vulnerability

CVE-2026-34356

High· 7.5CVSS7.5EPSS0%

.rules3/5

Heap-based Buffer Overflow vulnerability in Apache HTTP Server with malicious backend servers and ProxyPassReverseCookie* This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67. Users are recommended to upgrade to version 2.4.68

Threat signal

75/100

High

Severity

high

CVSS

7.5

EPSS

Active

CVSS

v3.1via NVDOpen in FIRST calculator →

7.5/ 10HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 ImpactNoneNo confidentiality impact.
Integrity ImpactNoneNo integrity impact.
Availability ImpactHighTotal loss of availability — full DoS possible.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

0.20%

probability of exploitation in next 30 days

p41

higher than 41% of all CVEs

3-day trend↑ 0pp

Low exploitation likelihood — defer if no other signals fire.

Vendor VEX

No VEX statements published for CVE-2026-34356. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCTrack

Total impact on non-trivial mission systems

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

Lifecycle

2026-06-08Published
2026-06-09Last modified1 source
2026-06-11Vendor advisory · microsoftCVE-2026-34356 — Apache HTTP Server: ProxyPassReverseCookieMap buffer overflow

Entity graph

2 nodes · 1 edges · click to pivot

CVEActorVendor advisoryIOCNews

Vendor advisories

microsoftCVE-2026-34356Apache HTTP Server: ProxyPassReverseCookieMap buffer overflow

References

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