CVE-2026-21910 describes an Improper Check for Unusual or Exceptional Conditions vulnerability in Juniper Networks Junos OS on EX4k and QFX5k Series platforms. An unauthenticated, network-adjacent attacker can cause a Denial of Service (DoS) by flapping an interface in an EVPN-VXLAN configuration, leading to traffic drops between VXLAN Network Identifiers (VNIs). This vulnerability has a CVSS score of 6.5 (Medium), indicating a low attack complexity with high availability impact. While there is no known active exploitation, public exploit code, or KEV listing, the vulnerability has garnered significant community discussion with 10 mentions.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 0, < 21.4R3-S12CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 22.4, < 22.4R3-S8CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 23.2, < 23.2R2-S5CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 23.4, < 23.4R2-S5CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 24.2, < 24.2R2-S3CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* |
CVSS version used by this source: 4.0
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:X/RE:M/U:Green
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.