Critical 9.0Known exploited (CISA KEV)Published Jul 14, 2021

CVE-2021-35211Serv-U Remote Memory Escape Vulnerability

Updated under an hour ago (2026-10-19 10:10 UTC)

Does this affect you?

It affects SolarWinds Serv-U Managed File Transfer Server and Serv-U Secured FTP and 1 other product. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Nov 3, 2021; federal agencies had to remediate by Nov 17, 2021, and it is known to be used in ransomware. Treat that date as your deadline.

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Every CVE for SolarWinds Serv-U Managed File Transfer Server and Serv-U Secured FTP

Exploited in the last 30 days

Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability.

CVSS: 9.0 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-787
Known exploited: Added to CISA KEV Nov 3, 2021; federal remediation due Nov 17, 2021; known ransomware useApply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 91.16% (percentile 100)
Assigned by: SolarWinds
NVD analysis: Analyzed
Record last updated: Oct 21, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

SolarWinds Serv-U Managed File Transfer Server and Serv-U Secured FTP solarwinds:serv_u_managed_file_transfer_server_and_serv_u_secured_ftp (from the name)	from SolarWinds Serv-U before 15.2.3 HF1	CNA record
solarwinds serv-u solarwinds:serv-u	before 15.2.3; 15.2.3; 15.2.3	NVD

References

https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211x-refsource-misc, patch, vendor-advisory
https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploitx-refsource-misc, patch, vendor-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35211us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.