CVE-2026-73446: Security Advisory 0160
Vulnerability summary
CVE-2026-73446 is a high (CVSS 7.4) Incorrect Behavior Order vulnerability in arista networks eos. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 17.4% of scored vulnerabilities.
Timeline
- 15-09-2026PublishedVulnerability first disclosed.
- 16-09-2026Last modifiedVulnerability information updated.
Description
On affected platforms running Arista EOS with IS-IS configured on a broadcast interface, an unauthenticated attacker can send a crafted IS-IS Hello Protocol Data Unit (PDU) that causes the device to tear down an established IS-IS adjacency. This may result in traffic disruption and loss of IP reachability for prefixes advertised through that adjacency.
CVSS metrics
4 scores · 2 sources · 2 versions- NVDNIST7.0HighCVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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:X/R:X/V:X/RE:X/U:X
- NVDNIST7.4HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS trend
Probability
0.27%
Chance of exploitation in the next 30 days
Percentile
17%
Versus all other CVEs
30-day change
Increase +0.02 pp
From 0.25% on 22-09-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Arista networks1 product
- eos≥ 4.36.0, ≤ 4.36.1F | ≥ 4.35.0, ≤ 4.35.5M | ≥ 4.34.0, ≤ 4.34.7.1M | ≥ 4.33.0, ≤ 4.33.9M | ≥ 4.32.0, < 4.33.0F | ≥ 4.31.0, < 4.32.0F
1 vendor · 1 product