CVE-2026-18238

The rpcap client code that processes a RPCAPMSGPACKET 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.

Database specific

{
    "cwe_ids": [
        "CWE-126",
        "CWE-1288"
    ],
    "cna_assigner": "Tcpdump",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "1.10.x"
                },
                {
                    "fixed": "1.10.7"
                }
            ]
        }
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18238.json"
}

References

Affected packages

Git / github.com/the-tcpdump-group/libpcap

Affected ranges

Type

GIT

Repo

https://github.com/the-tcpdump-group/libpcap

Events

Introduced

b525001719c0d86e191eabf55ba6fc37410868df

Last affected

82001f32ed9e76b0515a19ee0cc5be28c8ee0541

Database specific

Show details

{
    "source": "AFFECTED_FIELD",
    "extracted_events": [
        {
            "introduced": "1.8.x"
        },
        {
            "last_affected": "1.8.x"
        },
        {
            "introduced": "1.9.x"
        },
        {
            "last_affected": "1.9.x"
        }
    ]
}

Affected versions

1.*

1.8.x

1.9.x

libpcap-1.*

libpcap-1.8.0-bp

libpcap-1.8.1

libpcap-1.9-bp

libpcap-1.9.0-rc1

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-18238.json"