CVE-2026-34355

⚠️ high

Summary

A buffer overflow in mod_proxy_html in Apache HTTP Server 2.4.67 and earlier allows an attack by an untrusted backend. Users are recommended to upgrade to version 2.4.68, which fixes this issue.

CVSS Score

7.5

High

EPSS Score

0.6

Exploit Probability

Published Date

2026-06-08

First Seen: 2026-06-09

📊 Relative Risk Intelligence

This CVE is Moderate Risk - more severe than 69.0% of all 328,009 vulnerabilities in our database.

#101,817

Above average severity

Severity Percentile

🎯 CISA SSVC Assessment Updated: Jun 8, 2026

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

YES

Can be exploited automatically

💥 Technical Impact

Partial

Limited system impact

🏆 Discovered By

Elhanan Haenel Junhui Lee

SSVC data provided by CISA

Last Modified 2026-06-09

Source NVD 🔗

CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE IDs (Weakness Types)

CWE-122

📦 Affected Products 1

Vendor	Product	Status	Affected Versions
apache	http_server	Affected	> 2.4.0 < 2.4.68

🔗 References 2

https://httpd.apache.org/security/vulnerabilities_24...

Vendor Advisory

http://www.openwall.com/lists/oss-security/2026/06/08/6

Mailing List

🔗 Related CVEs 6

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-29167	⛔ critical	9.8	0.7	Use After Free vulnerability in Apache HTTP Server with mod_ldap in per-directory configuration This issue affects Apac...	2026-06-08
CVE-2026-29170	🔶 medium	6.1	0.6	A cross-site scripting vulnerability exists in mod_proxy_ftp's HTML directory list generation in Apache HTTP Server 2.4....	2026-06-08
CVE-2026-34356	⚠️ high	7.5	0.7	Heap-based Buffer Overflow vulnerability in Apache HTTP Server with malicious backend servers and ProxyPassReverseCookie...	2026-06-08
CVE-2026-42535	⛔ critical	9.1	0.6	A path handling issue in mod_dav_fs in Apache 2.4.67 and earlier allows a WebDAV content author to directly manipulate ...	2026-06-08
CVE-2026-42536	⚠️ high	7.5	0.5	Heap-based Buffer Overflow vulnerability in Apache HTTP Server with mod_xml2enc, xml2StartParse, and untrusted content ...	2026-06-08
CVE-2026-43951	🔶 medium	6.5	0.5	Out-of-bounds Read vulnerability in Apache HTTP Server with mod_headers and mod_mime and multiple response languages. T...	2026-06-08

These CVEs affect the same products