# CVE-2026-96423: Heap-based Buffer Overflow in Wireshark

Status: published. Published: 2026-09-29. Updated: 2026-11-03.

X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service

## Remediation

- fix: Upgrade to version 4.6.9 or above (source: CNA: GitLab)

## Affected products and versions

- Wireshark Foundation / Wireshark: ≥ 4.6.0; < 4.6.9 (affected, semver); ≥ 4.4.0; < 4.4.19 (affected, semver). Source: CNA: GitLab

## NVD configuration conditions

Affected CPE matches depend on the following AND/OR and negation conditions:

```json
[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:wireshark:wireshark:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "4.4.19",
            "versionStartIncluding": "4.4.0",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:wireshark:wireshark:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "4.6.9",
            "versionStartIncluding": "4.6.0",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]
```

## Severity and prioritization

- CVSS 3.1: 5.5 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H; source: CNA: GitLab

- CVSS 3.1: 7.1 (high); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H; source: NVD: nvd@nist.gov

- CVSS 3.1: 5.5 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H; source: NVD: cve@gitlab.com

- CISA KEV: No listing in collected sources

- EPSS: 0.14% as of 2026-11-03; percentile 3.48%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-122, CWE-125

## Exploit evidence

- exploit: https://gitlab.com/wireshark/wireshark/-/work_items/21563 (ADP: CISA-ADP)
- exploit: https://gitlab.com/wireshark/wireshark/-/work_items/21563 (cve@gitlab.com)
- exploit: https://gitlab.com/wireshark/wireshark/-/work_items/21563 (134c704f-9b21-4f2e-91b3-4a467353bcc0)

## References

- https://www.wireshark.org/security/wnpa-sec-2026-108.html (CNA: GitLab)

- https://gitlab.com/wireshark/wireshark/-/work_items/21563 (CNA: GitLab)

- https://gitlab.com/wireshark/wireshark/-/work_items/21563 (ADP: CISA-ADP; exploit)

- https://gitlab.com/wireshark/wireshark/-/work_items/21563 (cve@gitlab.com; Exploit, Vendor Advisory)

- https://www.wireshark.org/security/wnpa-sec-2026-108.html (cve@gitlab.com; Vendor Advisory)

- https://gitlab.com/wireshark/wireshark/-/work_items/21563 (134c704f-9b21-4f2e-91b3-4a467353bcc0; Exploit, Vendor Advisory)

## Provenance

- CNA: GitLab: https://www.cve.org/CVERecord?id=CVE-2026-96423; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-96423; retrieved 2026-11-04; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-96423; retrieved 2026-11-03; source updated Not reported

Revision: 9b54dbfe268885778f9767b4df09f0c8cf206d18be5a330f916e91517a82f114

Canonical: https://y2.dev/cve/CVE-2026-96423

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.