MEDIUM
CVE-2026-33523
CWE-443Published: May 4, 2026· Updated: May 4, 2026
6.5
CVSS v3.1
EPSS:0.16%probability of exploitation in 30 daysPercentile:36.8th
Official Description
HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.
This issue affects Apache HTTP Server: from through 2.4.66.
Users are recommended to upgrade to version 2.4.67, which fixes the issue.
Technical Analysis
CVE-2026-33523 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Affected Vendors & Products
Apache1 product
http server
Source: NVD CPE · 1 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (2)
→
https://httpd.apache.org/security/vulnerabilities_24.htmlVendor Advisory
→
http://www.openwall.com/lists/oss-security/2026/05/04/23Mailing List · Third Party Advisory
Quick Facts
CVE IDCVE-2026-33523
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-443
CISA KEVNo
EPSS (30d)0.16%
Affected1 vendor
PublishedMay 4, 2026
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-33523 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.