The 802.1q VLAN protocol allows remote attackers to bypass network segmentation and spoof…
Priority LOW 26Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- — Not recorded in CVSS 2.0
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · Partial · None
- Fix status
- No fix listed
Attack profile from CVSS 2.0 · NVD. Fix status from CNA.
Summary
The 802.1q VLAN protocol allows remote attackers to bypass network segmentation and spoof VLAN traffic via a message with two 802.1q tags, which causes the second tag to be redirected from a downstream switch after the first tag has been stripped, as demonstrated by Yersinia, aka "double-tagging VLAN jumping attack."
Why it matters now
EPSS 0.01611 76th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:vlan_protocol:vlan_protocol:802.1q:*:*:*:*:*:*:* | 802.1q | Vulnerable | Vlan Protocol |
- cpe:2.3:a:vlan_protocol:vlan_protocol:802.1q:*:*:*:*:*:*:* Versions 802.1q Vulnerable ·Vlan Protocol
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2005-4440
- 2026-10-03 Alias added: GHSA-9rvj-pj6p-4pj6
References
Sources
- CVE-2005-4440 · CVE Program
- CVE-2005-4440 · NVD
- FIRST EPSS
- GHSA-9rvj-pj6p-4pj6 · GitHub Advisory Database · CC BY 4.0
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