CVE Record
[ CRITICAL ]CVE-2021-35211
SolarWinds Serv-U Remote Code Execution Vulnerability
SolarWinds Serv-U contains an unspecified memory escape vulnerability which can allow for remote code execution.
- Vendor
- SolarWinds
- Product
- Serv-U
- CVSS
- 9.0
- EPSS (exploit probability)
- 91.2%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2021-35211 being exploited?
Yes. CISA added CVE-2021-35211 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 91.2% (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 SolarWinds Serv-U CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-28318 SolarWinds Serv-U Uncontrolled Resource Consumption Vulnerability | [ HIGH ] | 7.5 | 1.9% | |
| CVE-2024-28995 SolarWinds Serv-U Path Traversal Vulnerability | [ HIGH ] | 8.6 | 99.6% | |
| CVE-2021-35247 SolarWinds Serv-U Improper Input Validation Vulnerability | [ MEDIUM ] | 4.3 | 3.5% |