Double Free in Apache HTTP Server

CVE-2026-23918

Double Free and possible RCE vulnerability in Apache HTTP Server with the HTTP/2 protocol. This issue affects Apache HTTP Server: 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Vulnerability class: Double Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.497 (98.9th percentile), scored .

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 99th percentile — 98.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-23918: held from 0.497 to 0.497.

EPSS over last 30 days · oldest: 0.497 · newest: 0.497 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-23918?
CVE-2026-23918 is a high-severity vulnerability in Apache HTTP Server, classified under Double Free. CVSS score: 8.8/10. Published 2026-05-04.
How severe is CVE-2026-23918?
High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2026-23918 known to be exploited?
15 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.