# CVE-2026-18238

## Summary

- **CVE ID:** CVE-2026-18238
- **Severity:** MEDIUM
- **CVSS Score:** 5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N)
- **CWE:** CWE-1288, CWE-126
- **Published:** Sep 5, 2026
- **Last Modified:** Sep 8, 2026

## 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.

## Affected Products

- The Tcpdump Group — libpcap (1.8.x)
- The Tcpdump Group — libpcap (1.9.x)
- The Tcpdump Group — libpcap (1.10.x)

## References

- [CNA](https://github.com/the-tcpdump-group/libpcap/commit/b9590d482986d64673712460aae1d48d11fa0473)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.18%
- **EPSS Percentile:** 7.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._