CVE-2026-34475

Varnish Cache: Varnish Cache and Varnish Enterprise: Cache poisoning and authentication bypass via unchecked URL handling

Published Mar 27, 2026 CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed
Description
Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Varnish-software varnish Enterprise
Vinyl-cache
Vinyl-cache vinyl Cache
CPEs cpe:2.3:a:varnish-software:varnish_enterprise:*:*:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r10:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r11:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r1:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r2:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r3:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r4:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r5:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r6:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r7:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r8:*:*:*:*:*:*
cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r9:*:*:*:*:*:*
cpe:2.3:a:vinyl-cache:vinyl_cache:*:*:*:*:*:*:*:*
Vendors & Products Varnish-software varnish Enterprise
Vinyl-cache
Vinyl-cache vinyl Cache
Type Values Removed Values Added
Title Varnish Cache URL Handling Leading to Cache Poisoning and Authentication Bypass Varnish Cache: Varnish Cache and Varnish Enterprise: Cache poisoning and authentication bypass via unchecked URL handling
Weaknesses CWE-1286
References
Metrics threat_severity

None

threat_severity

Moderate

Type Values Removed Values Added
Title Varnish Cache URL Handling Leading to Cache Poisoning and Authentication Bypass
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass.
First Time appeared Varnish-software
Varnish-software varnish Cache
Weaknesses CWE-180
CPEs cpe:2.3:a:varnish-software:varnish_cache:*:*:*:*:*:*:*:*
Vendors & Products Varnish-software
Varnish-software varnish Cache
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Mar 27, 2026, 8:01 PM
Reserved
Mar 27, 2026, 7:40 PM
Status
Analyzed
Published
Mar 27, 2026, 8:16 PM
Modified
Oct 26, 2026, 10:10 PM
Severity
Moderate
Public date
Mar 27, 2026, 7:40 PM