What products are affected by CVE-2026-28318?

CVE-2026-28318 affects SolarWinds Serv-U. Refer to the vendor advisory and NVD record for affected versions.

What is the EPSS score for CVE-2026-28318?

CVE-2026-28318 has an EPSS score of 6.7%, placing it in the 91th percentile. This means it has a 6.7% probability of being exploited in the next 30 days, higher than 91% of all known vulnerabilities. EPSS (Exploit Prediction Scoring System) is maintained by FIRST and uses real-world threat data to estimate exploitation likelihood.

Actively Exploited — CISA KEV

CVE-2026-28318: SolarWinds Serv-U High-Severity Vulnerability

Severity: High | CVSS 3.1: 7.5 | Published: 2026-06-04 | KEV Added: 2026-06-05

What is CVE-2026-28318?

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

Technical Analysis

Weakness Classification

This vulnerability is classified as CWE-400 — Uncontrolled Resource Consumption. An attacker can cause the application to consume excessive resources (CPU, memory, disk, network), leading to denial of service.

Attack Vector Breakdown

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Impact Analysis

This vulnerability is exploitable over the network, meaning any system reachable via the internet or internal network is potentially at risk without physical access. The attack complexity is low, requires no special privileges, and needs no user interaction — making it straightforward to exploit at scale. Successful exploitation can result in total availability loss (denial of service). An attacker can cause the application to consume excessive resources (CPU, memory, disk, network), leading to denial of service.

Exploitation Probability (EPSS): 6.7% chance of exploitation in the next 30 days (91th percentile). While the base probability may appear low, inclusion in CISA KEV confirms real-world exploitation is already occurring.

Is CVE-2026-28318 being exploited?

Yes. CVE-2026-28318 is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, restricted to CVEs with confirmed active exploitation in the wild. CISA added this vulnerability on 2026-06-05. Inclusion in KEV triggers the patching mandate under BOD 22-01 for U.S. federal civilian agencies, with a remediation deadline of 2026-06-19.

How to fix CVE-2026-28318

Apply the security update issued by SolarWinds for Serv-U. If an immediate patch is not possible, consult the vendor advisory for mitigation guidance, restrict network exposure of the affected service, and monitor logs for indicators of exploitation. CISA's Known Exploited Vulnerabilities catalog requires U.S. federal agencies to remediate this vulnerability by the due date shown below under Binding Operational Directive 22-01. Private organizations should treat KEV entries as priority-one patches because active exploitation has been confirmed in the wild.

Related Vulnerabilities

Other actively exploited vulnerabilities affecting Serv-U or sharing the same weakness (CWE-400):

CVE-2026-45498 (Medium 4.0) [same CWE] — Microsoft Defender Denial of Service Vulnerability
CVE-2025-26399 (Critical 9.8) [same vendor] — SolarWinds Web Help Desk was found to be susceptible to an unauthenticated…
CVE-2025-40536 (High 8.1) [same vendor] — SolarWinds Web Help Desk was found to be susceptible to a security control…
CVE-2025-40551 (Critical 9.8) [same vendor] — SolarWinds Web Help Desk was found to be susceptible to an untrusted data…

Frequently asked questions

Is CVE-2026-28318 critical?

CVE-2026-28318 has a CVSS 3.1 base score of 7.5 — High severity. It should be treated as a priority patch, especially given the active exploitation confirmed by CISA.

Is CVE-2026-28318 being actively exploited?

Yes — CISA added CVE-2026-28318 to the Known Exploited Vulnerabilities catalog on 2026-06-05. Inclusion in KEV means CISA has confirmed in-the-wild exploitation.

How do I patch CVE-2026-28318?

Apply the security update from SolarWinds for Serv-U. Federal agencies must remediate by 2026-06-19 under BOD 22-01.

What type of vulnerability is CVE-2026-28318?

CVE-2026-28318 is classified under CWE-400 (Uncontrolled Resource Consumption). An attacker can cause the application to consume excessive resources (CPU, memory, disk, network), leading to denial of service.

What is the CVSS score for CVE-2026-28318?

CVE-2026-28318 has a CVSS 3.1 base score of 7.5, classifying it as High severity. The attack vector is Network, attack complexity is Low, and no privileges are required.