---
id: CVE-2026-76879
title: >-
  wireshark: Wireshark: Denial of Service via C12.22 protocol dissector crash
  (CVE-2026-76879)
summary: >-
  A flaw in Wireshark's C12.22 protocol dissector allows remote attackers to
  trigger a Denial of Service (DoS). By sending a specially crafted network
  packet or capture file, an attacker can crash the application, disrupting
  network analysis…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-617
  - CWE-121
vendor: Red Hat
product: Red Hat Enterprise Linux AppStream (v. 10)
affected:
  - enterprise_linux_appstream_v_10
  - enterprise_linux_codeready_linux_builder_v_10
patched:
  - enterprise_linux_appstream_v_10
  - enterprise_linux_codeready_linux_builder_v_10
published: '2026-08-19'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:23:50+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-76879.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-76879.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-76879'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2520098'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-76879'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76879'
  - url: 'https://gitlab.com/wireshark/wireshark/-/work_items/21480'
  - url: 'https://www.wireshark.org/security/wnpa-sec-2026-89.html'
  - url: 'https://access.redhat.com/errata/RHSA-2026:84721'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00312
epssPercentile: 0.23892
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-08-20T15:08:32.060760Z'
scores:
  vendor: 6.5
  cna: 7.5
ingestedAt: '2026-09-17T19:26:25.344Z'
---

## Overview

A flaw in Wireshark's C12.22 protocol dissector allows remote attackers to trigger a Denial of Service (DoS). By sending a specially crafted network packet or capture file, an attacker can crash the application, disrupting network analysis capabilities.

## Vendor advisories

- **RHSA-2026:84721** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:84721)
- **Red Hat VEX** · Moderate · updated 2026-09-29 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-76879.json)

**wireshark: Wireshark: Denial of Service via C12.22 protocol dissector crash** — rated Moderate by Red Hat. Released 2026-08-19, updated 2026-10-19.

Fixed:

- Red Hat Enterprise Linux AppStream (v. 10)
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9

## Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:84721

Workarounds / mitigations:

- Avoid analyzing capture files or live traffic from untrusted sources. If ANSI C12.22 parsing is not required, disable the dissector by unchecking C1222 under Analyze > Enabled Protocols in Wireshark, or by executing tshark with the -d c1222,0 flag.