CVE-2026-73459: Arista Networks EOS · Improper Validation of Integrity Check Value
Affects Arista Networks EOSSource CVE Database V5
Not known to be exploited · CVSS 7.4 High.
Data as of 30 Oct 2026, 20:25 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Arista NetworksEOS | Affected
| Fixed in– |
Aristaarista/eospkg:rpm/arista/eosOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, consider restricting IS-IS protocol access to trusted devices and networks to reduce exposure to unauthenticated injection attacks.
Description
CVE-2026-73459 is a high-severity vulnerability in Arista Networks EOS affecting versions 4.36.0 through 4.36.1F. It involves improper validation of integrity check values in the IS-IS protocol implementation. An unauthenticated attacker able to inject specially crafted IS-IS LSP PDUs can cause legitimate LSPs to be purged unexpectedly from the IS-IS link-state database, potentially resulting in traffic loss.