Low
libslirp — security advisory
A flaw was found in libslirp. When handling ICMP echo requests, the reply length is not updated to match the actual data received from the host. Under specific conditions where the normal ICMP socket is unavailable, this length mismatch causes the host's real IP address to be leaked to the guest in the echo reply, breaking the NAT isolation that user-mode networking is expected to provide.
- Products
- libslirp
- Affected versions
- 4.7.0-1, 4.8.0-1, 4.8.0-1+deb13u1, 4.9.1-1, 4.9.2-1, 4.9.3-1, 4.9.4-1, 4.9.5-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-115449
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 04:07 UTC · Revision 1
Source evidence
A flaw was found in libslirp. When handling ICMP echo requests, the reply length is not updated to match the actual data received from the host. Under specific conditions where the normal ICMP socket is unavailable, this length mismatch causes the host's real IP address to be leaked to the guest in the echo reply, breaking the NAT isolation that user-mode networking is expected to provide.
osv:DEBIAN-CVE-2026-115449
libslirp
Fixed versions: Not specified
libslirp
Fixed versions: Not specified
libslirp
Fixed versions: Not specified
Complete source record
{
"id": "307a908feba3a01db2e15dbec7d942b872e8670305c252f1a97e8cdf8f6030b1",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-115449",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-115449",
"summary": "A flaw was found in libslirp. When handling ICMP echo requests, the reply length is not updated to match the actual data received from the host. Under specific conditions where the normal ICMP socket is unavailable, this length mismatch causes the host's real IP address to be leaked to the guest in the echo reply, breaking the NAT isolation that user-mode networking is expected to provide.",
"evidence": "osv:DEBIAN-CVE-2026-115449",
"products": [
{
"name": {
"value": "libslirp",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.7.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.8.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.9.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.9.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.9.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.9.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.9.5-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
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"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.8.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.8.0-1+deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "4.9.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.9.2-1",
"evidence": "/affected/1/versions"
},
{
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"evidence": "/affected/1/versions"
},
{
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{
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}
]
},
{
"name": {
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},
"prerequisites": [],
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"affected_versions": [
{
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"evidence": "/affected/2/versions"
},
{
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"evidence": "/affected/2/versions"
},
{
"value": "4.9.2-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.9.3-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.9.4-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.9.5-1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "low",
"structured": {
"id": "DEBIAN-CVE-2026-115449",
"aliases": [
"DEBIAN-CVE-2026-115449"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "libslirp",
"purl": "pkg:deb/debian/libslirp?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"4.7.0-1",
"4.8.0-1",
"4.9.1-1",
"4.9.2-1",
"4.9.3-1",
"4.9.4-1",
"4.9.5-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-115449.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "libslirp",
"purl": "pkg:deb/debian/libslirp?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"4.8.0-1",
"4.8.0-1+deb13u1",
"4.9.1-1",
"4.9.2-1",
"4.9.3-1",
"4.9.4-1",
"4.9.5-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-115449.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
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}
],
"package": {
"name": "libslirp",
"purl": "pkg:deb/debian/libslirp?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"4.8.0-1",
"4.9.1-1",
"4.9.2-1",
"4.9.3-1",
"4.9.4-1",
"4.9.5-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-115449.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-24T09:47:31.920801060Z",
"provider": "osv",
"upstream": [
"CVE-2026-115449"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-115449"
]
},
"related_cves": [
{
"value": "CVE-2026-115449",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 429007,
"published_at": "2026-10-22T22:18:06.647+00:00"
}