Actively exploited KEV catalog No authentication
CVE-2026-28318

SolarWinds Serv-U Uncontrolled Resource Consumption Vulnerability

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…

CheckOps priority index
6.7/10 Patch within 7 days
Severity7.5
Probability4.4
Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 43.7% higher than 98.7% of CVEs
CVSS 3.1 7.5 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:
Exploited for 151 days 05 Jun 2026
CISA due date 19 Jun 2026 for US federal agencies

Exploitation probability EPSS · FIRST

05010025 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

  • KEV catalog (CISA)05 Jun 2026
  • Exploited in EUVD (ENISA)05 Jun 2026
  • Used by ransomwareno
  • EPSS above 10 %43.7%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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

Affected products

Serv-U
Affected versions
  • 0 ≤15.5.4
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 43.7%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2025-26399SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability
    9.6 · Background exploitation
  • CVE-2025-40536SolarWinds Web Help Desk Security Control Bypass Vulnerability
    7.8 · Background exploitation
  • CVE-2025-40551SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability
    8.8 · Background exploitation
  • CVE-2024-28987SolarWinds Web Help Desk Hardcoded Credential Vulnerability
    8.8 · Background exploitation
  • CVE-2024-28986SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability
    8.9 · Background exploitation
  • CVE-2024-28995SolarWinds Serv-U Path Traversal Vulnerability
    8.8 · Background exploitation

Are you affected?

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities