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
The record classifies CVE-2026-28318 under weakness class CWE-400. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 135 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.5 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS (FIRST)
- 1.9% probability of exploitation in the next 30 days, higher than 79.5% of all scored CVEs
- CISA KEV
- Listed since 2026-06-05, federal remediation deadline 2026-06-19
- Threadlinqs priority
- 9/10 — CISA KEV-listed, which Threadlinqs floors at 9
- Published
- 2026-06-04, last modified 2026-06-06
Is CVE-2026-28318 being exploited?
CISA added CVE-2026-28318 to the Known Exploited Vulnerabilities catalog on 2026-06-05, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-06-19 under BOD 22-01. Weaponised exploit code for CVE-2026-28318 is publicly available. 2 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 43 in the Threadlinqs vulnerability feed.
- EaEa0001/servu-cve-2026-28318-poc (github)
- BishopFox/CVE-2026-28318-check (github)
Affected products and versions
- SolarWinds: Serv-U
How to fix CVE-2026-28318
Vendor advisory: https://www.solarwinds.com/trust-center/security-advisories/CVE-2026-28318. Because CVE-2026-28318 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-06-19. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-28318
3 tracked threats in the Threadlinqs corpus reference CVE-2026-28318, either in the campaign’s CVE list or as an indicator on the campaign record.
- SolarWinds Access Rights Manager Hard-Coded Cryptographic Key (CVE-2026-28326) Enables Unauthenticated RCE — CRITICAL · 2026-09-19
- SolarWinds Serv-U 2026.3 Patches 16 Vulnerabilities (CVE-2026-28302 to CVE-2026-28321) Including Root RCE, IDOR-Chained Privilege Escalation, and Broken Access Control — CRITICAL · 2026-07-22
- SolarWinds Serv-U DoS (CVE-2026-28318) — Actively Exploited Uncontrolled Resource Consumption via Content-Encoding: deflate POST — HIGH · 2026-06-08
Sources
Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.