CVE-2026-28318
HighExploitedPublic exploitSolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate.
Published Jun 4, 2026 · Updated Jul 22, 2026 · Also known as EUVD-2026-34268, GHSA-4vx4-vp54-mwmc
Key Facts
Patch immediately- CVE-2026-28318 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting Serv-U (Solarwinds).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 5, 2026. Public exploit code is available.
- EPSS estimates a 1.9% probability of exploitation in the next 30 days.
- Fixed versions are available, including Serv-U 15.5.4.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
1.9%
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-28318 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Jun 5, 2026 | Jun 19, 2026 | Not reported |
| Industry KEV feed | Jun 5, 2026 | Jun 19, 2026 | Not reported |
| CIRCL KEV | Jun 5, 2026 | Jun 19, 2026 | Not reported |
| ENISA EUVD | Jun 5, 2026 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected Products
4 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Serv-USolarwinds | 15.5.4, >= 15.5.4 and previous versions | 15.5.4 |
Patched Releases
Serv-U
15.5.4
Timeline
Publicly disclosed
Jun 4, 2026
Added to CISA KEV
Jun 5, 2026
Added to Industry KEV feed
Jun 5, 2026
Added to CIRCL KEV
Jun 5, 2026
Added to ENISA EUVD
Jun 5, 2026
Last updated
Jul 22, 2026
Weakness Type
- CWE-400 Uncontrolled Resource Consumption
References
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- otherhttps://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-5-4-hotfix-1_release_notes.htm
- otherhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-28318
FAQ
Common Questions.
SolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate.
Affected: Serv-U (Solarwinds) versions 15.5.4, >= 15.5.4 and previous versions. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 5, 2026.
Yes. It was added on Jun 5, 2026 with a federal remediation due date of Jun 19, 2026.
Public exploit code is available.
Fixed versions are available, including Serv-U 15.5.4.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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