Buffer overflow in Apache HTTP Server
CVE-2026-34355
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.012 (67.0th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.027 · newest: 0.012 · change: -0.015
Affected products
- Apache HTTP Server
- Apache Software Foundation HTTP Server — versions 2.4.0
Weakness classification (CWE)
References
- httpd.apache.org/security/vulnerabilities_24.html (vendor-advisory, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-34355?
- CVE-2026-34355 is a high-severity vulnerability in Apache HTTP Server, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2026-06-08.
- How severe is CVE-2026-34355?
- High severity. CVSS v3 base score is 7.5 out of 10.