SolarWinds Serv-U Unauthenticated Denial of Service Vulnerability
Priority CRITICAL 90Exploited in the wildCWE-400Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-400.
Summary
SolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate. Mitigation steps are provided to secure customer environments in the SolarWinds Trust Center if you are unable to deploy the update
Why it matters now
Exploitation Active In CISA KEV since 2026-06-05CISA due date 2026-06-19
EPSS 0.48001 98th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Active
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| SolarWinds | Serv-U | up to 15.5.4 | — | No fix listed | CNA |
- Serv-U VendorSolarWinds Affected up to 15.5.4 Fixed in — No fix listed CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:solarwinds:serv-u:*:*:*:*:*:*:*:* | before 15.5.4 | Vulnerable | SolarWinds |
| cpe:2.3:a:solarwinds:serv-u:15.5.4:-:*:*:*:*:*:* | 15.5.4 | Vulnerable | SolarWinds |
- cpe:2.3:a:solarwinds:serv-u:*:*:*:*:*:*:*:* Versions before 15.5.4 Vulnerable ·SolarWinds
- cpe:2.3:a:solarwinds:serv-u:15.5.4:-:*:*:*:*:*:* Versions 15.5.4 Vulnerable ·SolarWinds
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-06-05 Added to CISA KEV
- 2026-10-02 Threatist record created from CVE-2026-28318
- 2026-10-03 Alias added: GHSA-4vx4-vp54-mwmc
- 2026-10-21 Affected versions changed · CNA
- 2026-10-23 EPSS moved to the 95th–99th percentile
References
More SolarWinds Serv-u vulnerabilities
- TI-2021-14105 Serv-U Remote Memory Escape Vulnerability KEVCVSS 3.1CRITICAL 10.0
- TI-2024-19183 SolarWinds Serv-U L Directory Transversal Vulnerability KEVCVSS 3.1HIGH 8.6
- TI-2021-14139 Improper Input Validation Vulnerability in Serv-U KEVCVSS 3.1MEDIUM 5.3
- TI-2024-30693 SolarWinds Serv-U FTP Service Directory Traversal Remote Code Execution Vulnerability CVSS 3.1HIGH 8.8
- TI-2021-14142 Directory Transversal Vulnerability in Serv-U 15.3 CVSS 3.1HIGH 7.5
- TI-2026-22617 SolarWinds Serv-U Insecure Direct Object Reference (IDOR) Vulnerability CVSS 3.1CRITICAL 9.1
Sources
- CVE-2026-28318 · CVE Program
- CVE-2026-28318 · NVD
- CISA Known Exploited Vulnerabilities
- FIRST EPSS
- GHSA-4vx4-vp54-mwmc · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences