Description
CMS protocol dissector crash in 4.6.0 to 4.6.7 and 4.4.0 to 4.4.18 allows denial of service
Published: 2026-08-19
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The vulnerability stems from a use‑after‑free bug in Wireshark's CMS protocol dissector, causing the application to crash when processing certain CMS packets. This leads to denial of service of the application and any dependent services that rely on Wireshark’s stability. The weakness corresponds to CWE‑416, indicating a flaw in memory management. Based on the description, it is inferred that a crafted CMS packet triggers the use‑after‑free, but explicit crash trigger details are not disclosed.

Affected Systems

Wireshark versions 4.6.0 through 4.6.7 and 4.4.0 through 4.4.18 are affected. Users running these releases should identify the exact minor version they are using and plan for an update.

Risk and Exploitability

The CVSS score of 5.5 reflects medium severity; no EPSS score is available and the vulnerability is not listed in the CISA KEV catalog. The likely attack vector is inferred to be through a crafted CMS packet delivered over a network or file opened by Wireshark; processing that packet triggers the crash. This local attack limits the impact to application instability rather than privilege escalation or data compromise.

Generated by OpenCVE AI on August 20, 2026 at 08:34 UTC.

Remediation

Vendor Solution

Upgrade to version 4.6.8 or above

OpenCVE Recommended Actions

  • Upgrade Wireshark to version 4.6.8 or later, which contains the fix for the CMS dissector use‑after‑free bug.
  • If immediate upgrade is not possible, disable the CMS protocol dissector in Wireshark preferences (Protocols → CMS) to prevent the crash when encountering CMS packets from untrusted sources.
  • Consider filtering or blocking CMS traffic from untrusted networks until a patched version is deployed, reducing the chance that malicious packets reach the dissector.

Generated by OpenCVE AI on August 20, 2026 at 08:34 UTC.

Tracking

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Advisories
Source ID Title
Debian DSA Debian DSA DSA-6471-1 wireshark security update
History

Mon, 31 Aug 2026 19:30:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:wireshark:wireshark:*:*:*:*:*:*:*:*

Fri, 21 Aug 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 20 Aug 2026 01:30:00 +0000

Type Values Removed Values Added
First Time appeared Wireshark
Wireshark wireshark
Vendors & Products Wireshark
Wireshark wireshark

Wed, 19 Aug 2026 23:00:00 +0000

Type Values Removed Values Added
Description CMS protocol dissector crash in 4.6.0 to 4.6.7 and 4.4.0 to 4.4.18 allows denial of service
Title Use After Free in Wireshark
Weaknesses CWE-416
References
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

Subscriptions

Wireshark Wireshark
cve-icon MITRE

Status: PUBLISHED

Assigner: GitLab

Published:

Updated: 2026-08-20T15:26:29.457Z

Reserved: 2026-08-19T22:44:30.531Z

Link: CVE-2026-76921

cve-icon Vulnrichment

Updated: 2026-08-20T15:22:58.709Z

cve-icon NVD

Status : Analyzed

Published: 2026-08-19T23:16:20.840

Modified: 2026-08-31T19:16:06.737

Link: CVE-2026-76921

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-20T08:45:12Z

Weaknesses