CVE-2026-18238

medium

Assigned by CNA: tcpdump

Published 2026-09-05 · Modified 2026-09-05

Discuss on Community Propose mitigation

CVSS v3

5.0

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

CVSS v4 NEW

—

not yet in upstream

VIR risk

5.0

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.

Predictions

Exploit likelihood

60%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

https://github.com/the-tcpdump-group/libpcap/commit/b9590d482986d64673712460aae1d48d11fa0473

CWEs

CWE-126 CWE-1288

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.