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Fencer Vulns
critical 9.8

CVE-2018-6836 json

The netmonrec_comment_destroy function in wiretap/netmon.c in Wireshark through 2.4.4 performs a free operation on an uninitialized memory…

published 2018-02-08 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-18582

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.7%
EPSS 2.7% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

The netmonrec_comment_destroy function in wiretap/netmon.c in Wireshark through 2.4.4 performs a free operation on an uninitialized memory address, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact.

Patch / fix

  • wireshark Ubuntu 14.04 LTS 2.6.3-1~ubuntu14.04.1
  • wireshark Ubuntu 16.04 LTS 2.6.3-1~ubuntu16.04.1
  • wireshark Ubuntu 18.04 LTS 2.6.3-1~ubuntu18.04.1

ubuntu advisories UBUNTU-CVE-2018-6836

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2018-6836 updated cvss 3.3

wireshark: free operation on an uninitialized memory address in wiretap/netmon.c

  • Red Hat Enterprise Linux 5 wireshark Red Hat Enterprise Linux 6 wireshark, wireshark-gnome Red Hat Enterprise Linux 7 wireshark, wireshark-gnome Red Hat Enterprise Linux 8 wireshark, wireshark-cli
    affected: no fix planned “Will not fix”

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

Exploit prediction

2.72% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugs.wireshark.org https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=14397 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-763 Release of Invalid Pointer or Reference

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.