symfony — security advisory
In Symfony before versions 4.4.7 and 5.0.7, when a `Response` does not contain a `Content-Type` header, affected versions of Symfony can fallback to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can prevent the use of the website by other users. This has been patched in versions 4.4.7 and 5.0.7.
- Products
- symfony
- Affected versions
- Not specified
- Fixed versions
- 4.4.8-1
- CVEs
- CVE-2020-5255
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 13:14 UTC · Revision 1
Source evidence
In Symfony before versions 4.4.7 and 5.0.7, when a `Response` does not contain a `Content-Type` header, affected versions of Symfony can fallback to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can prevent the use of the website by other users. This has been patched in versions 4.4.7 and 5.0.7.
osv:DEBIAN-CVE-2020-5255
symfony
Fixed versions: 4.4.8-1
symfony
Fixed versions: 4.4.8-1
symfony
Fixed versions: 4.4.8-1
Complete source record
{
"id": "cab876790a862f72ed2cb2853469606eb2b70599bf3e52c699c0147ef9d74900",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2020-5255",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2020-5255",
"summary": "In Symfony before versions 4.4.7 and 5.0.7, when a `Response` does not contain a `Content-Type` header, affected versions of Symfony can fallback to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can prevent the use of the website by other users. This has been patched in versions 4.4.7 and 5.0.7.",
"evidence": "osv:DEBIAN-CVE-2020-5255",
"products": [
{
"name": {
"value": "symfony",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.4.8-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "symfony",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.4.8-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "symfony",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.4.8-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2020-5255",
"aliases": [
"DEBIAN-CVE-2020-5255"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.4.8-1"
}
]
}
],
"package": {
"name": "symfony",
"purl": "pkg:deb/debian/symfony?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-5255.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.4.8-1"
}
]
}
],
"package": {
"name": "symfony",
"purl": "pkg:deb/debian/symfony?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-5255.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.4.8-1"
}
]
}
],
"package": {
"name": "symfony",
"purl": "pkg:deb/debian/symfony?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-5255.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-26T12:02:04.568643893Z",
"provider": "osv",
"upstream": [
"CVE-2020-5255"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2020-5255"
]
},
"related_cves": [
{
"value": "CVE-2020-5255",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 451989,
"published_at": "2020-03-30T20:15:19.57+00:00"
}