Critical
varnish — security advisory
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.
- Products
- varnish
- Affected versions
- 3.0.4-1ubuntu1, 3.0.4-1ubuntu2, 3.0.5-1ubuntu2, 3.0.5-2, 3.0.5-2ubuntu0.1, 4.0.3-1, 4.1.0-1, 4.1.0-2, 4.1.1-1, 4.1.1-1ubuntu0.2, 4.1.1-1ubuntu0.2+esm1, 5.0.0-7.1, 5.2.1-1, 5.2.1-1ubuntu0.1, 5.2.1-1ubuntu0.1+esm1, 6.1.1-1, 6.2.1-2, 6.2.1-2ubuntu0.1, 6.2.1-2ubuntu0.1~esm1, 6.2.1-2ubuntu0.1~esm2, 6.2.1-2ubuntu0.2, 6.2.1-2ubuntu0.2+esm1, 6.5.2-1, 6.6.1-1, 6.6.1-1ubuntu0.2, 6.6.1-1ubuntu0.2+esm1, 7.1.1-1.1ubuntu1, 7.7.0-1, 7.7.0-2, 7.7.0-3, 7.7.3-1, 7.7.3-1build1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-34475
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:00 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2026-34475
varnish
Fixed versions: Not specified
varnish
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varnish
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varnish
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varnish
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varnish
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varnish
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varnish
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varnish
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Complete source record
{
"id": "3c1b616e6a11ad635d0f85afe93347c04294c01e921cdad3d9def85252225569",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-34475",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-34475",
"summary": "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.",
"evidence": "osv:UBUNTU-CVE-2026-34475",
"products": [
{
"name": {
"value": "varnish",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.0.4-1ubuntu1",
"evidence": "/affected/0/versions"
},
{
"value": "3.0.4-1ubuntu2",
"evidence": "/affected/0/versions"
},
{
"value": "3.0.5-1ubuntu2",
"evidence": "/affected/0/versions"
},
{
"value": "3.0.5-2",
"evidence": "/affected/0/versions"
},
{
"value": "3.0.5-2ubuntu0.1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "varnish",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.0.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.1.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.1.0-2",
"evidence": "/affected/1/versions"
},
{
"value": "4.1.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.1.1-1ubuntu0.2",
"evidence": "/affected/1/versions"
},
{
"value": "4.1.1-1ubuntu0.2+esm1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "varnish",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.0.0-7.1",
"evidence": "/affected/2/versions"
},
{
"value": "5.2.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "5.2.1-1ubuntu0.1",
"evidence": "/affected/2/versions"
},
{
"value": "5.2.1-1ubuntu0.1+esm1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "varnish",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.1.1-1",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.1-2",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.1-2ubuntu0.1~esm1",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.1-2ubuntu0.1~esm2",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.1-2ubuntu0.1",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.1-2ubuntu0.2",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.1-2ubuntu0.2+esm1",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "varnish",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.5.2-1",
"evidence": "/affected/4/versions"
},
{
"value": "6.6.1-1",
"evidence": "/affected/4/versions"
},
{
"value": "6.6.1-1ubuntu0.2",
"evidence": "/affected/4/versions"
},
{
"value": "6.6.1-1ubuntu0.2+esm1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "varnish",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "7.1.1-1.1ubuntu1",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "varnish",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "7.7.0-1",
"evidence": "/affected/6/versions"
},
{
"value": "7.7.0-2",
"evidence": "/affected/6/versions"
},
{
"value": "7.7.0-3",
"evidence": "/affected/6/versions"
},
{
"value": "7.7.3-1",
"evidence": "/affected/6/versions"
}
]
},
{
"name": {
"value": "varnish",
"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "7.7.3-1build1",
"evidence": "/affected/7/versions"
}
]
},
{
"name": {
"value": "varnish",
"evidence": "/affected/8/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "7.7.3-1",
"evidence": "/affected/8/versions"
},
{
"value": "7.7.3-1build1",
"evidence": "/affected/8/versions"
}
]
}
],
"severity": "critical",
"structured": {
"id": "UBUNTU-CVE-2026-34475",
"aliases": [
"UBUNTU-CVE-2026-34475"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "varnish",
"purl": "pkg:deb/ubuntu/varnish?arch=source&distro=trusty",
"ecosystem": "Ubuntu:14.04:LTS"
},
"versions": [
"3.0.4-1ubuntu1",
"3.0.4-1ubuntu2",
"3.0.5-1ubuntu2",
"3.0.5-2",
"3.0.5-2ubuntu0.1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34475.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libvarnishapi1",
"binary_version": "3.0.5-2ubuntu0.1"
},
{
"binary_name": "varnish",
"binary_version": "3.0.5-2ubuntu0.1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "varnish",
"purl": "pkg:deb/ubuntu/varnish?arch=source&distro=esm-apps%2Fxenial",
"ecosystem": "Ubuntu:Pro:16.04:LTS"
},
"versions": [
"4.0.3-1",
"4.1.0-1",
"4.1.0-2",
"4.1.1-1",
"4.1.1-1ubuntu0.2",
"4.1.1-1ubuntu0.2+esm1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34475.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libvarnishapi1",
"binary_version": "4.1.1-1ubuntu0.2+esm1"
},
{
"binary_name": "varnish",
"binary_version": "4.1.1-1ubuntu0.2+esm1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "varnish",
"purl": "pkg:deb/ubuntu/varnish?arch=source&distro=esm-apps%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"versions": [
"5.0.0-7.1",
"5.2.1-1",
"5.2.1-1ubuntu0.1",
"5.2.1-1ubuntu0.1+esm1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34475.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libvarnishapi1",
"binary_version": "5.2.1-1ubuntu0.1+esm1"
},
{
"binary_name": "varnish",
"binary_version": "5.2.1-1ubuntu0.1+esm1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "varnish",
"purl": "pkg:deb/ubuntu/varnish?arch=source&distro=esm-apps%2Ffocal",
"ecosystem": "Ubuntu:Pro:20.04:LTS"
},
"versions": [
"6.1.1-1",
"6.2.1-2",
"6.2.1-2ubuntu0.1~esm1",
"6.2.1-2ubuntu0.1~esm2",
"6.2.1-2ubuntu0.1",
"6.2.1-2ubuntu0.2",
"6.2.1-2ubuntu0.2+esm1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34475.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libvarnishapi2",
"binary_version": "6.2.1-2ubuntu0.2+esm1"
},
{
"binary_name": "varnish",
"binary_version": "6.2.1-2ubuntu0.2+esm1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "varnish",
"purl": "pkg:deb/ubuntu/varnish?arch=source&distro=esm-apps%2Fjammy",
"ecosystem": "Ubuntu:Pro:22.04:LTS"
},
"versions": [
"6.5.2-1",
"6.6.1-1",
"6.6.1-1ubuntu0.2",
"6.6.1-1ubuntu0.2+esm1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34475.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libvarnishapi2",
"binary_version": "6.6.1-1ubuntu0.2+esm1"
},
{
"binary_name": "varnish",
"binary_version": "6.6.1-1ubuntu0.2+esm1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "varnish",
"purl": "pkg:deb/ubuntu/varnish?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"7.1.1-1.1ubuntu1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34475.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libvarnishapi3",
"binary_version": "7.1.1-1.1ubuntu1"
},
{
"binary_name": "varnish",
"binary_version": "7.1.1-1.1ubuntu1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "varnish",
"purl": "pkg:deb/ubuntu/varnish?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"7.7.0-1",
"7.7.0-2",
"7.7.0-3",
"7.7.3-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34475.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libvarnishapi3",
"binary_version": "7.7.3-1"
},
{
"binary_name": "varnish",
"binary_version": "7.7.3-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "varnish",
"purl": "pkg:deb/ubuntu/varnish?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"7.7.3-1build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34475.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libvarnishapi3",
"binary_version": "7.7.3-1build1"
},
{
"binary_name": "varnish",
"binary_version": "7.7.3-1build1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "varnish",
"purl": "pkg:deb/ubuntu/varnish?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"7.7.3-1",
"7.7.3-1build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34475.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libvarnishapi3",
"binary_version": "7.7.3-1build1"
},
{
"binary_name": "varnish",
"binary_version": "7.7.3-1build1"
}
]
}
}
],
"modified": "2026-10-17T13:00:01.445358160Z",
"provider": "osv",
"upstream": [
"CVE-2026-34475"
],
"references": [
"https://ubuntu.com/security/CVE-2026-34475",
"https://www.cve.org/CVERecord?id=CVE-2026-34475",
"https://vinyl-cache.org/security/VSV00018.html"
]
},
"related_cves": [
{
"value": "CVE-2026-34475",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/1/score"
},
"source_id": "core-osv",
"document_id": 360141,
"published_at": "2026-03-27T20:16:00+00:00"
}