8.2

CVE-2026-2379: Arista EOS IPsec Tunnel Sequence Number Mismatch via Interface Flaps when Anti-Replay is Disabled

Awaiting analysis
Published 05-06-2026Last modified 09-06-2026

Vulnerability summary

CVE-2026-2379 is a high (CVSS 8.2) vulnerability in arista networks eos. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 12.5% of scored vulnerabilities.

Overall risk
33/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.2/10
010
High · v4.0 (CVE.org)
EPSS score
0.23%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 05-06-2026
    PublishedVulnerability first disclosed.
  2. 09-06-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.23%

Chance of exploitation in the next 30 days

Percentile

13%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.23% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Arista networks1 product
  • 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, < 4.31.0 | ≥ 4.29.0F, < 4.30.0 | ≥ 4.28.0F, < 4.29.0 | ≥ 4.27.1F, < 4.28.0

1 vendor · 1 product

References

1 links