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Fencer Vulns
medium 5.0

CVE-2026-18238 json

OOBR in rpcap client in libpcap before 1.10.7

published 2026-09-05 2 mo ago modified 2026-09-08 2 mo ago also EUVD-2026-72021

cvss
5.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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.

Patch / fix

  • The Tcpdump Group libpcap 1.10.7
  • libpcap Debian 14 1.10.7-1

debian advisories DEBIAN-CVE-2026-18238

  • libpcap SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 1.10.5-160000.5.1
  • libpcap SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +8 more 1.10.1-150400.3.12.1
  • libpcap SLE Module for Package Hub 15 SP7, SLE Module for Basesystem 15 SP7 1.10.5-150700.3.13.1
  • libpcap Linux Micro 6.1 1.10.4-slfo.1.1_3.1
  • libpcap Linux Micro 6.0 1.10.4-5.1
  • libpcap SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 1.8.1-10.12.1
  • libpcap SLES for SAP 15 SP6, SLES 15 SP6-LTSS 1.10.4-150600.3.12.1

suse advisories SUSE-SU-2026:23892-1SUSE-SU-2026:23907-1SUSE-SU-2026:4239-1SUSE-SU-2026:4195-1SUSE-SU-2026:4194-1SUSE-SU-2026:4188-1

  • libpcap openSUSE Leap 16.0 1.10.5-160000.5.1
  • libpcap openSUSE Tumbleweed 1.10.7-1.1

opensuse advisories openSUSE-SU-2026:21940-1openSUSE-SU-2026:11744-1

  • libpcap Azure Linux 3.0 1.10.7-1

azure linux advisories AZL-99729

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-18238 updated cvss 5.0

libpcap: libpcap: Information disclosure via out-of-bounds read in rpcap client

  • Red Hat Enterprise Linux 6 libpcap Red Hat Enterprise Linux 7 libpcap Red Hat Enterprise Linux 8 libpcap Red Hat Enterprise Linux 9 libpcap Red Hat Enterprise Linux 10 libpcap Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    +1 more products
    Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.0 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

Affected products

  • The Tcpdump Group libpcap

Classification

Weakness
  • CWE-1288 Improper Validation of Consistency within Input
  • CWE-126 Buffer Over-read

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.