Public proof of conceptFix available

CVE-2026-23918

Q: Is CVE-2026-23918 actively exploited?

Active exploitation of CVE-2026-23918 has not been confirmed. Its EPSS score was 49.7% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2026-23918?

CVE-2026-23918 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

A public proof of concept exists; no exploitation attested.

Published2026-05-04
WeaknessCWE-1341 · CWE-415

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC

2026-05-0415:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 15:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-23918?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-23918?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Apache HTTP Server

Branch	Affected	Fixed in	Source
2.4	= 2.4.66	no fix published	NVD

apache

Branch	Affected	Fixed in	Source
2.4	≥ 2.4.66, < 2.4.67	2.4.67	OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

CVE-2026-23918 Red Hat Product Security4 products fixed
Apache HTTP Server: Apache HTTP Server: Remote Code Execution via Double Free in HTTP/2 Protocol
RHSA-2026:13938 Red Hat Product Security13 products fixed
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

Full record on NVD

Fix

Vendor fix Red Hat Product Security RHSA-2026:13938 · 13 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
Workaround from the vendor Red Hat Product Security RHSA-2026:13938 · 23 productsTo mitigate this issue, disable the `mod_http2` module in your Apache HTTP Server configuration. This can be achieved by commenting out or removing the `LoadModule http2_module modules/mod_http2.so` line in the Apache configuration file (e.g., `/etc/httpd/conf.modules.d/00-base.conf` or a similar c…

Advisories and patches

httpd.apache.orgVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: EDB-52577
Proof-of-concept repositories: 15 repositories, unverifiedqassam-315/CVE-2026-23918-Elite-Auditor12lie20/CVE-2026-23918-testrshosting/Apache-CVE-2026-23918-fixaa022/CVE-2026-23918-Passive-Auditrhasan-com/CVE-2026-23918

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionnone2026-05-04
OpenCVESSVC decisionnone—
CISA-ADPCVSS 3.18.82026-05-04
CNACVSS 3.18.8read 2026-10-23
CNAweakness (CWE)CWE-1341, CWE-415read 2026-10-23
FIRST EPSSEPSS score49.7 %2026-10-22
PoC-in-GitHubproof of concept15—
OSVaffected packages—
Microsoft MSRCadvisory—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Published: 2026-05-04
Last Modified: 2026-07-15
NVD status: Modified
MSRC Title: Apache HTTP Server: http2: double free and possible RCE on early reset

Frequently asked questions

What is CVE-2026-23918?

Is CVE-2026-23918 actively exploited?

Active exploitation of CVE-2026-23918 has not been confirmed. Its EPSS score was 49.7% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-23918?

CVE-2026-23918 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

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