Medium
libpcap — security advisory
The rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers. A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet.
- Products
- libpcap
- Affected versions
- 1.10.0-2build1, 1.10.1-4, 1.10.1-4build1, 1.10.1-4ubuntu1.22.04.1, 1.10.1-4ubuntu1.22.04.2, 1.10.4-4, 1.10.4-4.1ubuntu2, 1.10.4-4.1ubuntu3, 1.10.4-4.1ubuntu3.1, 1.10.4-4ubuntu3, 1.10.5-2ubuntu2, 1.10.5-2ubuntu3, 1.10.6-1ubuntu1, 1.10.6-1ubuntu1.1, 1.10.6-2ubuntu1, 1.10.7-1ubuntu1, 1.4.0-2, 1.5.1-1, 1.5.2-1, 1.5.3-1, 1.5.3-2, 1.5.3-2ubuntu0.1, 1.5.3-2ubuntu0.1+esm1, 1.7.4-1, 1.7.4-2, 1.7.4-2ubuntu0.1, 1.7.4-2ubuntu0.1+esm1, 1.8.1-5ubuntu1, 1.8.1-6ubuntu1, 1.8.1-6ubuntu1.18.04.1, 1.8.1-6ubuntu1.18.04.2, 1.8.1-6ubuntu1.18.04.2+esm1, 1.9.1-2, 1.9.1-3, 1.9.1-3ubuntu1.20.04.1, 1.9.1-3ubuntu1.20.04.1+esm1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-18238
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 01:24 UTC · Revision 1
Source evidence
The rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers. A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet.
osv:UBUNTU-CVE-2026-18238
libpcap
Fixed versions: Not specified
libpcap
Fixed versions: Not specified
libpcap
Fixed versions: Not specified
libpcap
Fixed versions: Not specified
libpcap
Fixed versions: Not specified
libpcap
Fixed versions: Not specified
libpcap
Fixed versions: Not specified
libpcap
Fixed versions: Not specified
Complete source record
{
"id": "b6609b6b9f57bba2570a3a3277a598961154d73d5f29cbe008ec3bd46f082254",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-18238",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-18238",
"summary": "The rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers. A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet.",
"evidence": "osv:UBUNTU-CVE-2026-18238",
"products": [
{
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},
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{
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"evidence": "/affected/0/versions"
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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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"evidence": "/affected/3/versions"
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{
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{
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"evidence": "/affected/4/versions"
},
{
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"evidence": "/affected/4/versions"
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{
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"evidence": "/affected/4/versions"
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{
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},
{
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},
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"affected_versions": [
{
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"evidence": "/affected/5/versions"
},
{
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"evidence": "/affected/5/versions"
},
{
"value": "1.10.4-4.1ubuntu2",
"evidence": "/affected/5/versions"
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{
"value": "1.10.4-4.1ubuntu3",
"evidence": "/affected/5/versions"
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{
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"evidence": "/affected/6/versions"
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{
"value": "1.10.6-2ubuntu1",
"evidence": "/affected/6/versions"
},
{
"value": "1.10.7-1ubuntu1",
"evidence": "/affected/6/versions"
}
]
},
{
"name": {
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"evidence": "/affected/7/package/name"
},
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"affected_versions": [
{
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"evidence": "/affected/7/versions"
},
{
"value": "1.10.5-2ubuntu3",
"evidence": "/affected/7/versions"
},
{
"value": "1.10.6-1ubuntu1",
"evidence": "/affected/7/versions"
},
{
"value": "1.10.6-1ubuntu1.1",
"evidence": "/affected/7/versions"
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]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-18238",
"aliases": [
"UBUNTU-CVE-2026-18238"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
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"type": "ECOSYSTEM",
"events": [
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}
]
}
],
"package": {
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"purl": "pkg:deb/ubuntu/libpcap?arch=source&distro=esm-infra-legacy%2Ftrusty",
"ecosystem": "Ubuntu:Pro:14.04:LTS"
},
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"database_specific": {
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{
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},
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{
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},
"versions": [
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"1.8.1-6ubuntu1.18.04.2",
"1.8.1-6ubuntu1.18.04.2+esm1"
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},
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}
],
"modified": "2026-10-17T12:56:47.647886563Z",
"provider": "osv",
"upstream": [
"CVE-2026-18238"
],
"references": [
"https://ubuntu.com/security/CVE-2026-18238",
"https://www.cve.org/CVERecord?id=CVE-2026-18238"
]
},
"related_cves": [
{
"value": "CVE-2026-18238",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 356283,
"published_at": "2026-09-05T19:16:00+00:00"
}