Vulnerability Details CVE-2026-33523
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.
Exploit prediction scoring system (EPSS) score
CVSS Severity
CVSS v3 Score 6.5
References
Products affected by CVE-2026-33523
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cpe:2.3:a:apache:http_server:2.4.0
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cpe:2.3:a:apache:http_server:2.4.1
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cpe:2.3:a:apache:http_server:2.4.10
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cpe:2.3:a:apache:http_server:2.4.11
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cpe:2.3:a:apache:http_server:2.4.12
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cpe:2.3:a:apache:http_server:2.4.13
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cpe:2.3:a:apache:http_server:2.4.14
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cpe:2.3:a:apache:http_server:2.4.15
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cpe:2.3:a:apache:http_server:2.4.16
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cpe:2.3:a:apache:http_server:2.4.17
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cpe:2.3:a:apache:http_server:2.4.18
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cpe:2.3:a:apache:http_server:2.4.19
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cpe:2.3:a:apache:http_server:2.4.2
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cpe:2.3:a:apache:http_server:2.4.20
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cpe:2.3:a:apache:http_server:2.4.21
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cpe:2.3:a:apache:http_server:2.4.22
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cpe:2.3:a:apache:http_server:2.4.23
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cpe:2.3:a:apache:http_server:2.4.24
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cpe:2.3:a:apache:http_server:2.4.25
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cpe:2.3:a:apache:http_server:2.4.26
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cpe:2.3:a:apache:http_server:2.4.27
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cpe:2.3:a:apache:http_server:2.4.28
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cpe:2.3:a:apache:http_server:2.4.29
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cpe:2.3:a:apache:http_server:2.4.3
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cpe:2.3:a:apache:http_server:2.4.30
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cpe:2.3:a:apache:http_server:2.4.31
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cpe:2.3:a:apache:http_server:2.4.32
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cpe:2.3:a:apache:http_server:2.4.33
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cpe:2.3:a:apache:http_server:2.4.34
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cpe:2.3:a:apache:http_server:2.4.35
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cpe:2.3:a:apache:http_server:2.4.36
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cpe:2.3:a:apache:http_server:2.4.37
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cpe:2.3:a:apache:http_server:2.4.38
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cpe:2.3:a:apache:http_server:2.4.39
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cpe:2.3:a:apache:http_server:2.4.4
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cpe:2.3:a:apache:http_server:2.4.40
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cpe:2.3:a:apache:http_server:2.4.41
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cpe:2.3:a:apache:http_server:2.4.42
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cpe:2.3:a:apache:http_server:2.4.43
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cpe:2.3:a:apache:http_server:2.4.44
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cpe:2.3:a:apache:http_server:2.4.45
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cpe:2.3:a:apache:http_server:2.4.46
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cpe:2.3:a:apache:http_server:2.4.47
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cpe:2.3:a:apache:http_server:2.4.48
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cpe:2.3:a:apache:http_server:2.4.49
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cpe:2.3:a:apache:http_server:2.4.5
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cpe:2.3:a:apache:http_server:2.4.50
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cpe:2.3:a:apache:http_server:2.4.51
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cpe:2.3:a:apache:http_server:2.4.52
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cpe:2.3:a:apache:http_server:2.4.53
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cpe:2.3:a:apache:http_server:2.4.54
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cpe:2.3:a:apache:http_server:2.4.55
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cpe:2.3:a:apache:http_server:2.4.56
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cpe:2.3:a:apache:http_server:2.4.57
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cpe:2.3:a:apache:http_server:2.4.58
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cpe:2.3:a:apache:http_server:2.4.59
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cpe:2.3:a:apache:http_server:2.4.6
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cpe:2.3:a:apache:http_server:2.4.60
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cpe:2.3:a:apache:http_server:2.4.61
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cpe:2.3:a:apache:http_server:2.4.62
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cpe:2.3:a:apache:http_server:2.4.63
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cpe:2.3:a:apache:http_server:2.4.64
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cpe:2.3:a:apache:http_server:2.4.65
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cpe:2.3:a:apache:http_server:2.4.66
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cpe:2.3:a:apache:http_server:2.4.7
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cpe:2.3:a:apache:http_server:2.4.8
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cpe:2.3:a:apache:http_server:2.4.9