CVE-2026-2379Arista EOS IPsec Tunnel Sequence Number Mismatch via Interface Flaps when Anti-Replay is Disabled
- 8.2HighCVSS base score
- 0.23%Exploitation in 30 daysEPSS · top 87% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
On affected platforms with hardware IPSec support running Arista EOS with certain IPsec features enabled, EOS may exhibit unexpected behavior in specific cases. Physical interface flaps and certain agent restarts can cause IPsec tunnel re-establishment with existing Security Associations, resulting in sequence number mismatches between tunnel endpoints potentially causing unstable communication.
Timeline
ID reserved
By Arista
- 4 months later
· 4 months later
Published
- 4 days later
· 4 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| AristaCNA (assigner) | 4.0 | High8.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| AristaCNA (assigner) | 3.1 | Medium5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
| NVDNVD · Awaiting Analysis | 4.0 | High8.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/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 (exploitation in 30 days)
- 0.23% · top 87% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.2.
Affected products
- affected 4.34.0 – ≤ 4.34.3M
- affected 4.33.0M – ≤ 4.33.5M
- affected 4.32.0M – ≤ 4.32.7M
- affected 4.31.0M – ≤ 4.31.9M
- affected 4.30.0F – < 4.31.0
- affected 4.29.0F – < 4.30.0
- affected 4.28.0F – < 4.29.0
- affected 4.27.1F – < 4.28.0
What to do
Solution: 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. For more information about upgrading see: EOS User Manual: Upgrades and Downgrades https://www.arista.com/en/um-eos/eos-upgrades-and-downgrades CVE-2026-2379 has been fixed in the following releases: * 4.35.0F and later releases in the 4.35.x train * 4.34.4M and later releases in the 4.34.x train * 4.33.6M and later releases in the 4.33.x train * 4.32.8M and later releases in the 4.32.x train * 4.31.10M and later releases in the 4.31.x train
Workaround: There is no known mitigation for CVE-2026-2379. The recommended resolution is to upgrade to a remediated software version at your earliest convenience.
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-34875 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-2379)Record last updated .