CVE-2026-20051 (GCVE-0-2026-20051)
Vulnerability from cvelistv5
Published
2026-02-25 16:14
Modified
2026-02-25 19:05
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-457 - Use of Uninitialized Variable
Summary
A vulnerability with the Ethernet VPN (EVPN) Layer 2 ingress packet processing of Cisco Nexus 3600 Platform Switches and Cisco Nexus 9500-R Series Switching Platforms could allow an unauthenticated, adjacent attacker to trigger a Layer 2 traffic loop.
This vulnerability is due to a logic error when processing a crafted Layer 2 ingress frame. An attacker could exploit this vulnerability by sending a stream of crafted Ethernet frames through the targeted device. A successful exploit could allow the attacker to cause a Layer 2 Virtual eXtensible LAN (VxLAN) traffic loop, which, in turn, could result in a denial of service (DoS) condition. This Layer 2 loop could oversubscribe the bandwidth on network interfaces, which would result in all data plane traffic being dropped. To exploit this vulnerability, the attacker must be Layer 2-adjacent to the affected device.
Note: To stop active exploitation of this vulnerability, manual intervention is required to both stop the crafted traffic and flap all involved network interfaces. For additional assistance if a Layer 2 loop that is related to this vulnerability is suspected, contact the Cisco Technical Assistance Center (TAC) or the proper support provider.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Cisco | Cisco NX-OS Software |
Version: 9.2(3) Version: 9.2(2v) Version: 9.2(1) Version: 9.2(2t) Version: 9.2(3y) Version: 9.3(2) Version: 9.2(4) Version: 9.3(1) Version: 9.3(1z) Version: 9.2(2) Version: 9.3(3) Version: 9.3(4) Version: 9.3(5) Version: 9.3(6) Version: 9.3(5w) Version: 9.3(7) Version: 9.3(7k) Version: 10.2(1) Version: 9.3(7a) Version: 9.3(8) Version: 10.2(1q) Version: 10.2(2) Version: 9.3(9) Version: 10.2(3) Version: 10.2(3t) Version: 9.3(10) Version: 10.2(2a) Version: 10.3(1) Version: 10.2(4) Version: 10.3(2) Version: 9.3(11) Version: 10.3(3) Version: 10.2(5) Version: 9.3(12) Version: 10.2(3v) Version: 10.4(1) Version: 10.2(6) Version: 10.3(3w) Version: 10.3(3o) Version: 10.3(4) Version: 10.3(3p) Version: 10.3(4a) Version: 10.4(2) Version: 10.3(3q) Version: 9.3(13) Version: 10.3(5) Version: 10.2(7) Version: 10.4(3) Version: 10.3(3x) Version: 10.3(4g) Version: 10.5(1) Version: 10.2(8) Version: 10.3(3r) Version: 10.3(6) Version: 9.3(14) Version: 10.4(4) Version: 10.3(4h) Version: 10.5(2) Version: 10.3(7) Version: 10.4(5) Version: 10.5(3) Version: 10.2(9) Version: 9.3(15) Version: 10.4(4g) Version: 10.5(4) Version: 10.6(1) Version: 10.5(3t) Version: 10.3(8) Version: 10.4(6) Version: 10.5(3s) Version: 10.5(3e) Version: 10.5(3o) Version: 9.3(16) Version: 10.6(1s) Version: 10.5(3p) |
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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