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Weekly Signal
Live intelligence Updated 20 Aug 2026 · 12:21 UTC

Accellion · Fta

CVE-2021-27104

Accellion FTA OS Command Injection Vulnerability

Recommended action

Validate affected assets and exposure now, then remediate on an accelerated schedule. Vendor advisory from www.accellion.com

View response plan
CVSS9.8
EPSS56.4%
KEVYes
ExploitationConfirmed exploitation
RemediationNot yet verified ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 56.4%; technical severity is CVSS 9.8.

Accellion FTA 9_12_370 and earlier is affected by OS command execution via a crafted POST request to various admin endpoints. The fixed version is FTA_9_12_380 and later.

Who should care

  • Teams operating Fta
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether Fta is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Vendor advisory from www.accellion.com
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Treatment intelligence

Remediation intelligence

Not yet verified

Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.

Verification noteAutomated link verification has not completed for this guidance yet.

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-20
Affected versions
Accellion Fta (End Including 9_12_370)
Fixed versions
No explicit fixed version is currently recorded.
Published
16 February 2021
Attack vector
Network
Privileges required
None
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 56.4%
  4. Signal calculated at 83

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.