# CVE-2026-28318 — SolarWinds Serv-U

**CISA KEV**

> As of 2026-06-06, CVE-2026-28318 is a HIGH-severity vulnerability in SolarWinds Serv-U, CVSS v3.1 7.5, EPSS 1.9% (79.5th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-06-05), with a US federal remediation deadline of 2026-06-19. Threadlinqs Intelligence links 3 tracked threat campaigns to CVE-2026-28318, most recently “SolarWinds Access Rights Manager Hard-Coded Cryptographic Key (CVE-2026-28326) Enables Unauthenticated RCE”.

**Last updated:** 2026-06-06

## 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](https://intel.threadlinqs.com/cwe/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](https://github.com/EaEa0001/servu-cve-2026-28318-poc) (github)
- [BishopFox/CVE-2026-28318-check](https://github.com/BishopFox/CVE-2026-28318-check) (github)

## Affected products and versions

- [SolarWinds](https://intel.threadlinqs.com/vendors/solarwinds): Serv-U

## How to fix CVE-2026-28318

Vendor advisory: [https://www.solarwinds.com/trust-center/security-advisories/CVE-2026-28318](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](https://intel.threadlinqs.com/threat/TL-2026-2585) — 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](https://intel.threadlinqs.com/threat/TL-2026-1625) — CRITICAL · 2026-07-22
- [SolarWinds Serv-U DoS (CVE-2026-28318) — Actively Exploited Uncontrolled Resource Consumption via Content-Encoding: deflate POST](https://intel.threadlinqs.com/threat/TL-2026-0717) — 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 2026-10-10. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [solarwinds.com](https://www.solarwinds.com/trust-center/security-advisories/CVE-2026-28318)
- [documentation.solarwinds.com](https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-5-4-hotfix-1_release_notes.htm)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-28318
Full detection coverage and IOCs for threats exploiting CVE-2026-28318 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp