Arista EOS IPsec Tunnel Sequence Number Mismatch via Interface Flaps when Anti-Replay is Disabled
Priority LOW 35CWE-672Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00226 13th percentileScored 2026-11-07
Fix Fixed EOS (Arista Networks): 4.31.0, 4.30.0, 4.29.0 +1
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Arista | EOS | 4.34.0 – 4.34.3M; 4.33.0M – 4.33.5M; 4.32.0M – 4.32.7M; 4.31.0M – 4.31.9M; 4.30.0F to before 4.31.0; 4.29.0F to before 4.30.0; 4.28.0F to before 4.29.0; 4.27.1F to before 4.28.0 | 4.31.0, 4.30.0, 4.29.0, 4.28.0 | Patch available | CNA |
- EOS VendorArista Affected 4.34.0 – 4.34.3M; 4.33.0M – 4.33.5M; 4.32.0M – 4.32.7M; 4.31.0M – 4.31.9M; 4.30.0F to before 4.31.0; 4.29.0F to before 4.30.0; 4.28.0F to before 4.29.0; 4.27.1F to before 4.28.0 Fixed in 4.31.0, 4.30.0, 4.29.0, 4.28.0 Patch available CNA
Remediation
- Fix · CNA EOS (Arista Networks) Fixed in 4.31.0, 4.30.0, 4.29.0, 4.28.0
Timeline
- 2026-10-02 Threatist record created from CVE-2026-2379
- 2026-10-03 Alias added: GHSA-qm38-553v-42w8
References
More Arista vulnerabilities
- TI-2026-79524 Privilege escalation in Arista VeloCloud Orchestrator on-premises KEVCVSS 4.0CRITICAL 9.4
- TI-2026-63212 Improper input validation in Arista VeloCloud Orchestrator On-Prem KEVCVSS 4.0CRITICAL 9.5
- TI-2026-13992 VeloCloud Orchestrator OS Command Injection KEVCVSS 4.0CRITICAL 10.0
- TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
- TI-2026-23989 crypto: algif_aead - Revert to operating out-of-place KEVCVSS 3.1HIGH 7.8
Sources
- CVE-2026-2379 · CVE Program
- CVE-2026-2379 · NVD
- FIRST EPSS
- GHSA-qm38-553v-42w8 · GitHub Advisory Database · CC BY 4.0
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