Security Advisory 0172
Summary
| CVE | CVE-2026-73438 |
|---|---|
| State | PUBLISHED |
| Assigner | Arista |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-16 10:16:51 UTC |
| Updated | 2026-09-16 19:17:30 UTC |
| Description | On affected platforms running Arista EOS with Open Shortest Path First version 3 (OSPFv3) configured, an unauthenticated attacker on the same OSPFv3 broadcast domain can send a specially crafted set of packets that can cause the Ospf3 agent to restart unexpectedly. The crash results in the loss of all OSPFv3 adjacencies on the affected device and may disrupt routing across the broader OSPF domain until the agent recovers. This issue was reported externally by Dravanet Inc., and Arista is not aware of any malicious exploitation of this vulnerability in customer networks. |
Risk And Classification
Primary CVSS: v4.0 7 HIGH from [email protected]
CVSS: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
EPSS: 0.002140000 probability, percentile 0.119290000 (date 2026-09-16)
Problem Types: CWE-617 | CWE-617 CWE-617 Reachable Assertion
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 7 | HIGH | CVSS: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/C... |
| 4.0 | CNA | CVSS | 7 | HIGH | CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H |
| 3.1 | [email protected] | Secondary | 5.3 | MEDIUM | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 5.3 | MEDIUM | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v4.0 Breakdown
CVSS: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
CVSS v3.1 Breakdown
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Arista Networks | EOS | affected 4.36.0F 4.36.1F custom | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
| CNA | Arista Networks | EOS | affected 4.35.0F 4.35.5M custom | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
| CNA | Arista Networks | EOS | affected 4.34.0F 4.34.7M custom | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
| CNA | Arista Networks | EOS | affected 4.33.0F 4.33.9M custom | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
| CNA | Arista Networks | EOS | affected 1.0.0 4.33.0F custom | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.arista.com/en/support/advisories-notices/security-advisory/24728-securit... | [email protected] | www.arista.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Dravanet Inc. (en)
Additional Advisory Data
Solutions
CNA: The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Arista recommends customers move to the latest version of each release that contains all the fixes listed below. CVE-2026-73438 has been fixed in the following releases: - 4.36.2F and later releases in the 4.36.x train - 4.35.6M and later releases in the 4.35.x train - 4.34.8M and later releases in the 4.34.x train - 4.33.10M and later releases in the 4.33.x train No hotfix is available for this issue.
Workarounds
CNA: The OSPFv3 authentication feature helps to mitigate this vulnerability. OSPFv3 authentication prevents unauthorized actors from injecting crafted packets into the OSPF domain. Enabling it on all OSPFv3-speaking interfaces ensures that packets from unauthenticated senders are discarded before they can trigger this vulnerability. Per-interface OSPFv3 encryption: Configure ESP-based encryption with authentication on each OSPFv3 interface. All peers on the same interface must use the same SPI, algorithm, and passphrase. switch(config)# interface <interface-name> switch(config-if)# ospfv3 encryption ipsec spi <spi-value> esp aes-256-cbc sha1 passphrase <shared-passphrase> Per-area OSPFv3 configuration: Configure ESP-based encryption with authentication on each OSPFv3 area. switch(config)# router ospfv3 switch(config-router-ospfv3)# address-family ipv4 switch(config-router-ospfv3-af)# area <area-id> encryption ipsec spi <spi-value> esp aes-256-cbc sha1 passphrase <shared-passphrase> switch(config-router-ospfv3-af)# address-family ipv6 switch(config-router-ospfv3-af)# area <area-id> encryption ipsec spi <spi-value> esp aes-256-cbc sha1 passphrase <shared-passphrase> Caution: Enabling OSPFv3 authentication must be coordinated across peering neighbors simultaneously. Applying this configuration to a single peer will temporarily break the routing adjacency, resulting in traffic disruption.