6.5

CVE-2026-77190: Security Advisory 0177

Awaiting analysis
Published 16-09-2026Last modified 16-09-2026

Vulnerability summary

CVE-2026-77190 is a medium (CVSS 6.5) Improper Input Validation vulnerability in arista networks eos. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 19.4% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.28%
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. 16-09-2026
    PublishedVulnerability first disclosed.
  2. 16-09-2026
    Last modifiedVulnerability information updated.

Description

On affected platforms running Arista EOS, an unauthenticated attacker who is network-adjacent to the switch and able to connect to a device with PIM Sparse Mode and MLAG configured, can send malformed messages that cause the Pimsm agent to terminate unexpectedly. The Pimsm agent is automatically restarted, but repeated attacks can cause the agent to restart continuously, resulting in a sustained denial of service.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.28%

Chance of exploitation in the next 30 days

Percentile

19%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.28% 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≥ 4.36.0F, ≤ 4.36.1F | ≥ 4.35.0F, ≤ 4.35.5M | ≥ 4.34.2F, ≤ 4.34.7M

1 vendor · 1 product

References

1 links