What is CVE-2026-33857?

CVE-2026-33857 is a medium-severity vulnerability in Apache Http_server, classified under Out-of-bounds Read. CVSS score: 5.3/10. Published 2026-05-04.

How severe is CVE-2026-33857?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Out-of-bounds Read in Apache Http_server

CVE-2026-33857

Out-of-bounds Read vulnerability in mod_proxy_ajp of Apache HTTP Server. This issue affects Apache HTTP Server: through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (44.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Apache Http_server
Apache Software Foundation Http Server — versions 0

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

security@apache.org (vendor-advisory, Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2026-33857?: CVE-2026-33857 is a medium-severity vulnerability in Apache Http_server, classified under Out-of-bounds Read. CVSS score: 5.3/10. Published 2026-05-04.
How severe is CVE-2026-33857?: Medium severity. CVSS v3 base score is 5.3 out of 10.