CVE-2026-73458
On affected platforms running Arista EOS with authenticated Bidirectional Forwarding Detection (BFD) sessions configured, a specially crafted packet can cause the BFD session(s) to go down. This may result in undesirable network changes because various rou
02 Description
On affected platforms running Arista EOS with authenticated Bidirectional Forwarding Detection (BFD) sessions configured, a specially crafted packet can cause the BFD session(s) to go down. This may result in undesirable network changes because various rou
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.40% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 34.0% of scored records. A rank, not a probability.
- NVD base score
- 9.2 (CVSS v4.0), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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
- NVD analysis status
- Awaiting Analysis. NVD last modified this record on 2026-09-16.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-09-15 19:30Z1 MO AGO
- Last updated
- 2026-09-15 19:38Z1 MO AGO
- Reserved
- 2026-08-12
- Assigning CNA
- Arista
- Record state
- PUBLISHED
- Severity
- Critical (CVSS 9.2)
- CNA CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:H
- Weaknesses
- CWE-303Incorrect Implementation of Authentication AlgorithmBase
- Data version
- 5.2
- Document digest
- 3b238e8869f1d94637caf1ea34f3c71557a3f5f5af9acf4c0e85c404ae0d47c1
05 Affected products
06 References
07 Remediation
The recommended resolution is to upgrade to a remediated software version at your earliest convenience. CVE-2026-73458 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 * 4.33.9M and later releases in the 4.33.x train