Patchfirst
CVE-2026-28318 KEVPublic exploit High · 7.5 EPSS 43.7%

SolarWinds Serv-U Uncontrolled Resource Consumption Vulnerability

SolarWinds · Serv-U

Summary

The flaw is an uncontrolled resource consumption weakness in SolarWinds Serv-U, where specially crafted POST requests using Content-Encoding: deflate can crash the Serv-U service. An unauthenticated attacker with network access can trigger the crash by sending such requests, requiring no user interaction or special configuration.

Official description · NVD

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

Breakdown
73.0 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
2/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

  2. What they do

First seen exploited 1 day after disclosure. Public exploit code (PoC-in-GitHub) appeared 6 days after disclosure.

  1. Disclosedday 0
  2. First seen exploitedVulnCheck KEV evidenceAdded to CISA KEVEU database agrees+1 day
  3. Public exploit codePoC-in-GitHub+6 days

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

2 , grouped by in kill-chain order, 2 cited passages 2

Initial AccessTA0001

Exploit Public-Facing Application T1190 Medium
AI mapping from the description · how it is exploited

Unauthenticated remote HTTP request exploits public-facing app

susceptible to specially crafted POST requests
From the official description (NVD) Original (opens in a new tab) ↗

ImpactTA0040

Endpoint Denial of Service T1499 Medium
AI mapping from the description · primary impact

Crash causes denial of service to the service

crash the Serv-U service without authentication
From the official description (NVD) Original (opens in a new tab) ↗

Detection

0 rules for this CVE · 152 general rules for its techniques

Rules for this CVE

0 that reference CVE-2026-28318 directly.

CVE-specific rules are not available in this build. Search SigmaHQ ↗

General rules for this CVE’s techniques

These detect the technique in general, not this specific vulnerability.

Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.

What security researchers reported

Not named in any threat report yet

Also mentioned in 50 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

3 links, grouped by NVD tag
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