Investigate in your agent.

Turn this advisory into a focused investigation. Ask your agent to check your project’s versions, explain the evidence, and suggest a compatible fix.

Your agent needs remote MCP support and access to https://cve.new/mcp.

Read the setup guide

Skip to content
cve.newCreate a CVE report
Check your stack
CVE-2026-121291

Security Advisory 0222

Products / packages Arista Networks EOS

Published

Share

Severity and exploitation

Not in CISA KEV

KEV coverage does not rule out exploitation.

KEV checked 15/11/2026, 00:45:32 UTC
Arista · CVSS:3.1 · 8.2
Assessment vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
Arista · CVSS:4.0 · 8.3
Assessment vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:L/SA:N
The headline uses the highest imported catalog score. Assessments can differ by source and CVSS version.

Severity

high8.3

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Not established by this record

Missing evidence does not mean no public exploit exists.

Remediation

Fix status not established

No structured fix or guidance is available here. Check the latest publisher advisory.

What this means

A crafted Error Report can cause Arista EOS versions 4.35.0F to 4.35.6M, 4.36.0F to 4.36.2F, and 4.37.0F to malfunction, preventing certain updates. The weakness is due to incorrect behavior order. Local access may be required to exploit this vulnerability.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Arista Networks · Arista

EOS

3 ranges
Arista version evidence
Platforms: 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6/XE7 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, ZTX-7200 Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance

Compare with this publisher’s ranges. This does not inspect your installation.

affected

4.37.0F

custom versions

4.36.0F → through 4.36.2F

custom versions

4.35.0F → through 4.35.6M

custom versions

unaffected

unknown

Other versions: unaffected

Automatic dependency matching is unavailable for this record. Use the product evidence and publisher’s instructions to check your installation.

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.

Original source description

Read the full publisher description

A crafted Error Report can leave EOS stuck believing that a cache reset is in progress, preventing ROA publication, withdrawal reconciliation, and BGP origin-validation updates.

References

1 sources
www.arista.com/en/support/advisories-notices/security-advisory/25044-security-advisory-0222
Vendor advisoryArista

Inside the record

Evidence available

Package identity · not supplied
Version evidence
Remediation guidance · not supplied
Weakness classification
Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-121291

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-696 ↗

CWE-696 Incorrect Behavior Order

Arista

Related →
Contributing organizations · 2
Arista

Assigning organization

2026-11-10
CISA-ADP

Additional data publisher

2026-11-13

Timeline

All times UTC

  1. Advisory published

    Publication date supplied by the source.

  2. Source updated

    Latest modification date supplied by the source.

  3. Last imported by cve.new

    Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes
  1. CVE · CVE-2026-121291

    Observed 2026-11-14T02:37:58.169Z · upstream updated 2026-11-13T17:27:40.172Z

    Prioritization updated

    before

    []

    after

    [
  {
    "source": "CISA-ADP",
    "type": "SSVC",
    "role": "CISA Coordinator",
    "timestamp": "2026-11-13T17:27:27.385133Z",
    "decisions": [
      {
        "name": "Exploitation",
        "value": "none"
      },
      {
        "name": "Automatable",
        "value": "yes"
      },
      {
        "name": "Technical Impact",
        "value": "partial"
      }
    ]
  }
]

Large field values are marked as truncated previews. Original source snapshots remain retained.

Showing up to 50 most recent observed changes.