HighFix available
squid — security advisory
An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of memory consumption.
- Products
- squid
- Affected versions
- Not specified
- Fixed versions
- 4.15-r0, 5.0.6-r0
- CVEs
- CVE-2021-28651
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 22:03 UTC · Revision 1
Source evidence
An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of memory consumption.
osv:ALPINE-CVE-2021-28651
squid
Fixed versions: 4.15-r0
squid
Fixed versions: 4.15-r0
squid
Fixed versions: 4.15-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
squid
Fixed versions: 5.0.6-r0
Complete source record
{
"id": "aa7eea24fe764695e0f82c8d68929ec5a472bbc9755a65c5c24829914b1db036",
"url": "https://osv.dev/vulnerability/ALPINE-CVE-2021-28651",
"method": "structured",
"payload": {
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"title": "ALPINE-CVE-2021-28651",
"summary": "An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of memory consumption.",
"evidence": "osv:ALPINE-CVE-2021-28651",
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{
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{
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{
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{
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"severity": "high",
"structured": {
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"aliases": [
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],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
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"database_specific": {
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},
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{
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],
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},
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{
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],
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"ecosystem": "Alpine:v3.24"
},
"database_specific": {
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}
],
"modified": "2026-10-23T17:17:56.169402111Z",
"provider": "osv",
"upstream": [
"CVE-2021-28651"
],
"references": [
"https://security.alpinelinux.org/vuln/CVE-2021-28651"
]
},
"related_cves": [
{
"value": "CVE-2021-28651",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 415378,
"published_at": "2021-05-27T12:15:08.197+00:00"
}