CVE-2026-18238
Received
Received - Intake
Buffer Overflow in libpcap RPCAP Client
Vulnerability report for CVE-2026-18238, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-05
Last updated on: 2026-09-05
Assigner: Tcpdump Group
Description
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| tcpdump | libpcap | to 20 (inc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-126 | The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer. |
| CWE-1288 | The product receives a complex input with multiple elements or fields that must be consistent with each other, but it does not validate or incorrectly validates that the input is actually consistent. |
