CVE-2026-18238
MEDIUMDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 7% of all known CVEs.
References
Related Vulnerabilities
Other CWE-126 (Buffer Over-read) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2023-49285 | High | 8.6 | 88% | - | Fix |
| CVE-2017-7668 | High | 7.5 | 57% | - | Fix |
| CVE-2017-7679 | Critical | 9.8 | 39% | - | Fix |
| CVE-2025-21277 | High | 7.5 | 39% | - | Fix |
| CVE-2024-38071 | High | 7.5 | 36% | - | Fix |
| CVE-2009-2495 | Medium | 6.5 | 34% | - | - |
Common questions
How do I fix CVE-2026-18238?
Upgrade libpcap on debian unstable to 1.10.7-1 or later.
Is CVE-2026-18238 being actively exploited?
Not that we know of. CVE-2026-18238 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.18% is the estimated probability that it will be exploited in the next 30 days. That is higher than 7% of all scored CVEs.
How severe is CVE-2026-18238?
CVE-2026-18238 has a CVSS v3 base score of 5.0, rated moderate. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-18238 affect?
Published advisories record a fix for libpcap (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-18238
Markdown
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TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-09-08.