Accellion FTA OS Command Injection Vulnerability
Accellion FTA contains an OS command injection vulnerability exploited via a crafted POST request to various admin endpoints.
- Vendor
- Accellion
- Product
- FTA
- CVSS
- 9.8
- EPSS (exploit probability)
- 56.7%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2021-27104 being exploited?
Yes. CISA added CVE-2021-27104 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 56.7% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-10-21. Full cross-catalog view: /kev-comparison
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (14 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Accellion FTA CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2021-27103 Accellion FTA Server-Side Request Forgery (SSRF) Vulnerabilityransomware use | [ CRITICAL ] | 9.8 | 11.4% | |
| CVE-2021-27102 Accellion FTA OS Command Injection Vulnerabilityransomware use | [ HIGH ] | 7.8 | 3.7% | |
| CVE-2021-27101 Accellion FTA SQL Injection Vulnerabilityransomware use | [ CRITICAL ] | 9.8 | 6.0% |