CVE Record
[ MEDIUM ]CVE-2021-35247
SolarWinds Serv-U Improper Input Validation Vulnerability
SolarWinds Serv-U versions 15.2.5 and earlier contain an improper input validation vulnerability that allows attackers to build and send queries without sanitization.
- Vendor
- SolarWinds
- Product
- Serv-U
- CVSS
- 4.3
- EPSS (exploit probability)
- 3.5%
- Status
- kev
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2021-35247 being exploited?
Yes. CISA added CVE-2021-35247 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 3.5% (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-2021-35211 SolarWinds Serv-U Remote Code Execution Vulnerabilityransomware use | [ CRITICAL ] | 9.0 | 91.2% |