puma — security advisory
Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, Puma is vulnerable to source IP spoofing when set_remote_address proxy_protocol: :v1 is enabled and persistent connections are used because Puma incorrectly re-parses PROXY protocol headers after each keep-alive request on the same connection, allowing an attacker to inject a second PROXY header and overwrite REMOTE_ADDR. This issue is fixed in versions 7.2.1 and 8.0.2.
- Products
- puma
- Affected versions
- 5.6.5-3, 5.6.5-3+deb12u1, 6.6.0-4, 8.0.2-1, 8.0.2-2, 8.0.2-3
- Fixed versions
- 5.6.5-3+deb12u2, 8.0.2-1
- CVEs
- CVE-2026-47737
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 04:01 UTC · Revision 1
Source evidence
Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, Puma is vulnerable to source IP spoofing when set_remote_address proxy_protocol: :v1 is enabled and persistent connections are used because Puma incorrectly re-parses PROXY protocol headers after each keep-alive request on the same connection, allowing an attacker to inject a second PROXY header and overwrite REMOTE_ADDR. This issue is fixed in versions 7.2.1 and 8.0.2.
osv:DEBIAN-CVE-2026-47737
puma
Fixed versions: 5.6.5-3+deb12u2
puma
Fixed versions: Not specified
puma
Fixed versions: 8.0.2-1
Complete source record
{
"id": "5463dfcb9d808bf371f5032c35817fed99f5aecd29b9cdf4e1817bd8d244d451",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-47737",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-47737",
"summary": "Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, Puma is vulnerable to source IP spoofing when set_remote_address proxy_protocol: :v1 is enabled and persistent connections are used because Puma incorrectly re-parses PROXY protocol headers after each keep-alive request on the same connection, allowing an attacker to inject a second PROXY header and overwrite REMOTE_ADDR. This issue is fixed in versions 7.2.1 and 8.0.2.",
"evidence": "osv:DEBIAN-CVE-2026-47737",
"products": [
{
"name": {
"value": "puma",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.6.5-3+deb12u2",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "5.6.5-3",
"evidence": "/affected/0/versions"
},
{
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"evidence": "/affected/0/versions"
}
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{
"name": {
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"affected_versions": [
{
"value": "6.6.0-4",
"evidence": "/affected/1/versions"
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{
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"evidence": "/affected/1/versions"
},
{
"value": "8.0.2-2",
"evidence": "/affected/1/versions"
},
{
"value": "8.0.2-3",
"evidence": "/affected/1/versions"
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{
"name": {
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],
"affected_versions": [
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}
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}
],
"severity": "high",
"structured": {
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"aliases": [
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"metrics": [
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"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
}
],
"affected": [
{
"ranges": [
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"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.6.5-3+deb12u2"
}
]
}
],
"package": {
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"purl": "pkg:deb/debian/puma?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
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"5.6.5-3+deb12u1"
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"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-47737.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
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"events": [
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"package": {
"name": "puma",
"purl": "pkg:deb/debian/puma?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"6.6.0-4",
"8.0.2-1",
"8.0.2-2",
"8.0.2-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-47737.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
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},
{
"ranges": [
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"type": "ECOSYSTEM",
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{
"fixed": "8.0.2-1"
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],
"package": {
"name": "puma",
"purl": "pkg:deb/debian/puma?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
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],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-47737.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-07T12:00:07.664437867Z",
"provider": "osv",
"upstream": [
"CVE-2026-47737"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-47737"
]
},
"related_cves": [
{
"value": "CVE-2026-47737",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 95007,
"published_at": "2026-07-14T20:17:03.767+00:00"
}