Accellion flaws being used in attacks

CISA lists 4 flaws in Accellion products as being used in attacks, most recently on 3 Nov 2021. All have been used in ransomware.

What to do

1. Update every Accellion product you use.Install the updates Accellion offers, on every device, and restart when asked. Each flaw below has a fix or clear advice; that’s one of CISA’s conditions for listing it.
2. If someone looks after IT for you, send them this page.Many of these are in equipment you don’t see: routers, firewalls, servers, the office network. Ask them to confirm each one is fixed, or that you don’t use the product.
3. Check anything else in the lookup.Search any app, company or CVE. Not being on CISA’s list doesn’t mean safe: keep updating either way.

Every flaw, newest first

1. Being used in attacksUsed in ransomwareAdded by CISA on 3 Nov 2021
   Accellion FTA
   CVE-2021-27104Accellion FTA OS Command Injection Vulnerability
   Accellion FTA contains an OS command injection vulnerability exploited via a crafted POST request to various admin endpoints.
   CISA’s required actionApply updates per vendor instructions.
   CVE recordNVD
2. Being used in attacksUsed in ransomwareAdded by CISA on 3 Nov 2021
   Accellion FTA
   CVE-2021-27103Accellion FTA Server-Side Request Forgery (SSRF) Vulnerability
   Accellion FTA contains a server-side request forgery (SSRF) vulnerability exploited via a crafted POST request to wmProgressstat.html.
   CISA’s required actionApply updates per vendor instructions.
   CVE recordNVD
3. Being used in attacksUsed in ransomwareAdded by CISA on 3 Nov 2021
   Accellion FTA
   CVE-2021-27102Accellion FTA OS Command Injection Vulnerability
   Accellion FTA contains an OS command injection vulnerability exploited via a local web service call.
   CISA’s required actionApply updates per vendor instructions.
   CVE recordNVD
4. Being used in attacksUsed in ransomwareAdded by CISA on 3 Nov 2021
   Accellion FTA
   CVE-2021-27101Accellion FTA SQL Injection Vulnerability
   Accellion FTA contains a SQL injection vulnerability exploited via a crafted host header in a request to document_root.html.
   CISA’s required actionApply updates per vendor instructions.
   CVE recordNVD

From CISA’s Known Exploited Vulnerabilities catalog, updated 21 Oct 2026 (version 2026.10.21). CISA’s required actions are written for US government agencies. Accellion on CISA’s site.