HighFix available
squid, squid3 — security advisory
Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Affected versions of squid are subject to a a Use-After-Free bug which can lead to a Denial of Service attack via collapsed forwarding. All versions of Squid from 3.5 up to and including 5.9 configured with "collapsed_forwarding on" are vulnerable. Configurations with "collapsed_forwarding off" or without a "collapsed_forwarding" directive are not vulnerable. This bug is fixed by Squid version 6.0.1. Users are advised to upgrade. Users unable to upgrade should remove all collapsed_forwarding lines from their squid.conf.
- Products
- squid, squid3
- Affected versions
- 3.3.8-1ubuntu16, 3.3.8-1ubuntu17, 3.5.12-1ubuntu6, 3.5.12-1ubuntu7, 3.5.12-1ubuntu7.1, 3.5.12-1ubuntu7.10, 3.5.12-1ubuntu7.11, 3.5.12-1ubuntu7.12, 3.5.12-1ubuntu7.13, 3.5.12-1ubuntu7.14, 3.5.12-1ubuntu7.15, 3.5.12-1ubuntu7.16, 3.5.12-1ubuntu7.16+esm1, 3.5.12-1ubuntu7.16+esm2, 3.5.12-1ubuntu7.16+esm3, 3.5.12-1ubuntu7.16+esm4, 3.5.12-1ubuntu7.16+esm5, 3.5.12-1ubuntu7.16+esm6, 3.5.12-1ubuntu7.16+esm7, 3.5.12-1ubuntu7.2, 3.5.12-1ubuntu7.3, 3.5.12-1ubuntu7.4, 3.5.12-1ubuntu7.5, 3.5.12-1ubuntu7.6, 3.5.12-1ubuntu7.7, 3.5.12-1ubuntu7.8, 3.5.12-1ubuntu7.9, 3.5.23-5ubuntu1, 3.5.23-5ubuntu2, 3.5.27-1ubuntu1, 3.5.27-1ubuntu1.1, 3.5.27-1ubuntu1.10, 3.5.27-1ubuntu1.11, 3.5.27-1ubuntu1.12, 3.5.27-1ubuntu1.13, 3.5.27-1ubuntu1.14, 3.5.27-1ubuntu1.14+esm1, 3.5.27-1ubuntu1.14+esm2, 3.5.27-1ubuntu1.14+esm3, 3.5.27-1ubuntu1.14+esm4, 3.5.27-1ubuntu1.14+esm5, 3.5.27-1ubuntu1.14+esm6, 3.5.27-1ubuntu1.2, 3.5.27-1ubuntu1.3, 3.5.27-1ubuntu1.4, 3.5.27-1ubuntu1.5, 3.5.27-1ubuntu1.6, 3.5.27-1ubuntu1.7, 3.5.27-1ubuntu1.8, 3.5.27-1ubuntu1.9, 4.10-1ubuntu1, 4.10-1ubuntu1.1, 4.10-1ubuntu1.10, 4.10-1ubuntu1.11, 4.10-1ubuntu1.2, 4.10-1ubuntu1.3, 4.10-1ubuntu1.4, 4.10-1ubuntu1.5, 4.10-1ubuntu1.6, 4.10-1ubuntu1.7, 4.10-1ubuntu1.8, 4.10-1ubuntu1.9, 4.13-10ubuntu5, 4.8-1ubuntu2, 4.8-1ubuntu3, 4.9-2ubuntu1, 4.9-2ubuntu2, 4.9-2ubuntu3, 4.9-2ubuntu4, 5.2-1ubuntu1, 5.2-1ubuntu3, 5.2-1ubuntu4, 5.2-1ubuntu4.1, 5.2-1ubuntu4.2, 5.2-1ubuntu4.3, 5.7-0ubuntu0.22.04.1, 5.7-0ubuntu0.22.04.2, 5.7-0ubuntu0.22.04.3
- Fixed versions
- 4.10-1ubuntu1.12, 5.7-0ubuntu0.22.04.4
- CVEs
- CVE-2023-49288
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 13:26 UTC · Revision 1
Source evidence
Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Affected versions of squid are subject to a a Use-After-Free bug which can lead to a Denial of Service attack via collapsed forwarding. All versions of Squid from 3.5 up to and including 5.9 configured with "collapsed_forwarding on" are vulnerable. Configurations with "collapsed_forwarding off" or without a "collapsed_forwarding" directive are not vulnerable. This bug is fixed by Squid version 6.0.1. Users are advised to upgrade. Users unable to upgrade should remove all collapsed_forwarding lines from their squid.conf.
osv:UBUNTU-CVE-2023-49288
squid3
Fixed versions: Not specified
squid3
Fixed versions: Not specified
squid
Fixed versions: 4.10-1ubuntu1.12
squid
Fixed versions: 5.7-0ubuntu0.22.04.4
Complete source record
{
"id": "ecb7623002eb3219b515416cf2cb6d0fb2817c37c7defe73e9d07f09a7b15301",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2023-49288",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2023-49288",
"summary": "Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Affected versions of squid are subject to a a Use-After-Free bug which can lead to a Denial of Service attack via collapsed forwarding. All versions of Squid from 3.5 up to and including 5.9 configured with \"collapsed_forwarding on\" are vulnerable. Configurations with \"collapsed_forwarding off\" or without a \"collapsed_forwarding\" directive are not vulnerable. This bug is fixed by Squid version 6.0.1. Users are advised to upgrade. Users unable to upgrade should remove all collapsed_forwarding lines from their squid.conf.",
"evidence": "osv:UBUNTU-CVE-2023-49288",
"products": [
{
"name": {
"value": "squid3",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.3.8-1ubuntu16",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.8-1ubuntu17",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu6",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.2",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.3",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.4",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.5",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.6",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.7",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.8",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.9",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.10",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.11",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.12",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.13",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.14",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.15",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.16",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.16+esm1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.16+esm2",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.16+esm3",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.16+esm4",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.16+esm5",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.16+esm6",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.12-1ubuntu7.16+esm7",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "squid3",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.5.23-5ubuntu1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.23-5ubuntu2",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.2",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.3",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.4",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.5",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.6",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.7",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.8",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.9",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.10",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.11",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.12",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.13",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.14",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.14+esm1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.14+esm2",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.14+esm3",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.14+esm4",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.14+esm5",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.27-1ubuntu1.14+esm6",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "squid",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.10-1ubuntu1.12",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "4.8-1ubuntu2",
"evidence": "/affected/2/versions"
},
{
"value": "4.8-1ubuntu3",
"evidence": "/affected/2/versions"
},
{
"value": "4.9-2ubuntu1",
"evidence": "/affected/2/versions"
},
{
"value": "4.9-2ubuntu2",
"evidence": "/affected/2/versions"
},
{
"value": "4.9-2ubuntu3",
"evidence": "/affected/2/versions"
},
{
"value": "4.9-2ubuntu4",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.1",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.2",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.3",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.4",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.5",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.6",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.7",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.8",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.9",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.10",
"evidence": "/affected/2/versions"
},
{
"value": "4.10-1ubuntu1.11",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "squid",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.7-0ubuntu0.22.04.4",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": [
{
"value": "4.13-10ubuntu5",
"evidence": "/affected/3/versions"
},
{
"value": "5.2-1ubuntu1",
"evidence": "/affected/3/versions"
},
{
"value": "5.2-1ubuntu3",
"evidence": "/affected/3/versions"
},
{
"value": "5.2-1ubuntu4",
"evidence": "/affected/3/versions"
},
{
"value": "5.2-1ubuntu4.1",
"evidence": "/affected/3/versions"
},
{
"value": "5.2-1ubuntu4.2",
"evidence": "/affected/3/versions"
},
{
"value": "5.2-1ubuntu4.3",
"evidence": "/affected/3/versions"
},
{
"value": "5.7-0ubuntu0.22.04.1",
"evidence": "/affected/3/versions"
},
{
"value": "5.7-0ubuntu0.22.04.2",
"evidence": "/affected/3/versions"
},
{
"value": "5.7-0ubuntu0.22.04.3",
"evidence": "/affected/3/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2023-49288",
"aliases": [
"UBUNTU-CVE-2023-49288"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "squid3",
"purl": "pkg:deb/ubuntu/squid3?arch=source&distro=esm-infra-legacy%2Fxenial",
"ecosystem": "Ubuntu:Pro:16.04:LTS"
},
"versions": [
"3.3.8-1ubuntu16",
"3.3.8-1ubuntu17",
"3.5.12-1ubuntu6",
"3.5.12-1ubuntu7",
"3.5.12-1ubuntu7.1",
"3.5.12-1ubuntu7.2",
"3.5.12-1ubuntu7.3",
"3.5.12-1ubuntu7.4",
"3.5.12-1ubuntu7.5",
"3.5.12-1ubuntu7.6",
"3.5.12-1ubuntu7.7",
"3.5.12-1ubuntu7.8",
"3.5.12-1ubuntu7.9",
"3.5.12-1ubuntu7.10",
"3.5.12-1ubuntu7.11",
"3.5.12-1ubuntu7.12",
"3.5.12-1ubuntu7.13",
"3.5.12-1ubuntu7.14",
"3.5.12-1ubuntu7.15",
"3.5.12-1ubuntu7.16",
"3.5.12-1ubuntu7.16+esm1",
"3.5.12-1ubuntu7.16+esm2",
"3.5.12-1ubuntu7.16+esm3",
"3.5.12-1ubuntu7.16+esm4",
"3.5.12-1ubuntu7.16+esm5",
"3.5.12-1ubuntu7.16+esm6",
"3.5.12-1ubuntu7.16+esm7"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-49288.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "squid",
"binary_version": "3.5.12-1ubuntu7.16+esm7"
},
{
"binary_name": "squid-cgi",
"binary_version": "3.5.12-1ubuntu7.16+esm7"
},
{
"binary_name": "squid-common",
"binary_version": "3.5.12-1ubuntu7.16+esm7"
},
{
"binary_name": "squid-purge",
"binary_version": "3.5.12-1ubuntu7.16+esm7"
},
{
"binary_name": "squid3",
"binary_version": "3.5.12-1ubuntu7.16+esm7"
},
{
"binary_name": "squidclient",
"binary_version": "3.5.12-1ubuntu7.16+esm7"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "squid3",
"purl": "pkg:deb/ubuntu/squid3?arch=source&distro=esm-infra%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"versions": [
"3.5.23-5ubuntu1",
"3.5.23-5ubuntu2",
"3.5.27-1ubuntu1",
"3.5.27-1ubuntu1.1",
"3.5.27-1ubuntu1.2",
"3.5.27-1ubuntu1.3",
"3.5.27-1ubuntu1.4",
"3.5.27-1ubuntu1.5",
"3.5.27-1ubuntu1.6",
"3.5.27-1ubuntu1.7",
"3.5.27-1ubuntu1.8",
"3.5.27-1ubuntu1.9",
"3.5.27-1ubuntu1.10",
"3.5.27-1ubuntu1.11",
"3.5.27-1ubuntu1.12",
"3.5.27-1ubuntu1.13",
"3.5.27-1ubuntu1.14",
"3.5.27-1ubuntu1.14+esm1",
"3.5.27-1ubuntu1.14+esm2",
"3.5.27-1ubuntu1.14+esm3",
"3.5.27-1ubuntu1.14+esm4",
"3.5.27-1ubuntu1.14+esm5",
"3.5.27-1ubuntu1.14+esm6"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-49288.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "squid",
"binary_version": "3.5.27-1ubuntu1.14+esm6"
},
{
"binary_name": "squid-cgi",
"binary_version": "3.5.27-1ubuntu1.14+esm6"
},
{
"binary_name": "squid-common",
"binary_version": "3.5.27-1ubuntu1.14+esm6"
},
{
"binary_name": "squid-purge",
"binary_version": "3.5.27-1ubuntu1.14+esm6"
},
{
"binary_name": "squid3",
"binary_version": "3.5.27-1ubuntu1.14+esm6"
},
{
"binary_name": "squidclient",
"binary_version": "3.5.27-1ubuntu1.14+esm6"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.10-1ubuntu1.12"
}
]
}
],
"package": {
"name": "squid",
"purl": "pkg:deb/ubuntu/squid?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"4.8-1ubuntu2",
"4.8-1ubuntu3",
"4.9-2ubuntu1",
"4.9-2ubuntu2",
"4.9-2ubuntu3",
"4.9-2ubuntu4",
"4.10-1ubuntu1",
"4.10-1ubuntu1.1",
"4.10-1ubuntu1.2",
"4.10-1ubuntu1.3",
"4.10-1ubuntu1.4",
"4.10-1ubuntu1.5",
"4.10-1ubuntu1.6",
"4.10-1ubuntu1.7",
"4.10-1ubuntu1.8",
"4.10-1ubuntu1.9",
"4.10-1ubuntu1.10",
"4.10-1ubuntu1.11"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-49288.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "squid",
"binary_version": "4.10-1ubuntu1.12"
},
{
"binary_name": "squid-cgi",
"binary_version": "4.10-1ubuntu1.12"
},
{
"binary_name": "squid-common",
"binary_version": "4.10-1ubuntu1.12"
},
{
"binary_name": "squid-purge",
"binary_version": "4.10-1ubuntu1.12"
},
{
"binary_name": "squidclient",
"binary_version": "4.10-1ubuntu1.12"
}
],
"availability": "No subscription required"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.7-0ubuntu0.22.04.4"
}
]
}
],
"package": {
"name": "squid",
"purl": "pkg:deb/ubuntu/squid?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"4.13-10ubuntu5",
"5.2-1ubuntu1",
"5.2-1ubuntu3",
"5.2-1ubuntu4",
"5.2-1ubuntu4.1",
"5.2-1ubuntu4.2",
"5.2-1ubuntu4.3",
"5.7-0ubuntu0.22.04.1",
"5.7-0ubuntu0.22.04.2",
"5.7-0ubuntu0.22.04.3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-49288.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "squid",
"binary_version": "5.7-0ubuntu0.22.04.4"
},
{
"binary_name": "squid-cgi",
"binary_version": "5.7-0ubuntu0.22.04.4"
},
{
"binary_name": "squid-common",
"binary_version": "5.7-0ubuntu0.22.04.4"
},
{
"binary_name": "squid-openssl",
"binary_version": "5.7-0ubuntu0.22.04.4"
},
{
"binary_name": "squid-purge",
"binary_version": "5.7-0ubuntu0.22.04.4"
},
{
"binary_name": "squidclient",
"binary_version": "5.7-0ubuntu0.22.04.4"
}
],
"availability": "No subscription required"
}
}
],
"modified": "2026-10-20T22:45:08.301560031Z",
"provider": "osv",
"upstream": [
"CVE-2023-49288"
],
"references": [
"https://ubuntu.com/security/CVE-2023-49288",
"https://github.com/squid-cache/squid/security/advisories/GHSA-rj5h-46j6-q2g5",
"https://megamansec.github.io/Squid-Security-Audit/trace-uaf.html",
"https://ubuntu.com/security/notices/USN-6728-1",
"https://ubuntu.com/security/notices/USN-6728-2",
"https://www.cve.org/CVERecord?id=CVE-2023-49288",
"https://ubuntu.com/security/notices/USN-6728-3"
]
},
"related_cves": [
{
"value": "CVE-2023-49288",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 390727,
"published_at": "2023-12-04T23:15:00+00:00"
}