OOBR in rpcap client in libpcap before 1.10.7

Answer in brief

CVE-2026-18238 records a Unknown severity vulnerability in OOBR in rpcap client in libpcap before 1.10.7. The current sources do not mark it as known exploited. The current feed maps The Tcpdump Group/libpcap (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 5, 2026Updated Sep 5, 2026Source checked Sep 5, 2026First seen by HOL Sep 5, 2026Material review Sep 5, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps The Tcpdump Group/libpcap (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
The Tcpdump Group/libpcapgeneric	1.8.x \|\| 1.9.x \|\| >=1.10.x <1.10.7	1.10.7

Recommended response

Check inventory. Check lockfiles and deployed manifests for The Tcpdump Group/libpcap.
Review the reported fix. Update The Tcpdump Group/libpcap to 1.10.7 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 5, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 5, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 5, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.