CVE-2026-28318: SolarWinds Serv-U Uncontrolled Resource Consumption Vulnerability

Q: How do I fix CVE-2026-28318?

serv-u: upgrade to 15.5.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-28318 being exploited?

Yes. CVE-2026-28318 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2026-28318 affect?

CVE-2026-28318 affects serv-u. Severity is high (CVSS 7.5). 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

Q: How urgent is CVE-2026-28318?

Priority 81/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Remotely exploitable, no login, no user action

Patch now

HIGH 7.5EXPLOITEDREMOTEUPGRADE

CVE-2026-28318 is a high-severity flaw (CVSS 7.5) affecting serv-u, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	43.7% (top 1%)
CISA exploited list	Yes, fix due 2026-06-19
Weakness	CWE-400
Published	2026-06-04
Last modified	2026-10-21

Publisher (CNA): SolarWinds · Vendor: solarwinds

Last updated 2026-10-21 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-04 15:16 UTCPublished CVE record published
2026-06-05Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-06-19Deadline CISA due date for US federal agencies to patch
2026-10-21 11:17 UTCUpdated Record last modified

solarwinds serv-u UPGRADE

Affected: < 15.5.4 · 15.5.4

Fixed in: 15.5.4

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy serv-u || rpm -q serv-u || serv-u --version

2. UPGRADE to 15.5.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade serv-u

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade serv-u

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Fedora 46 · arm-none-eabi-binutils-cs · FIXED · 2.47-1.fc46 · FEDORA-2026-7498616952 · source

sudo dnf upgrade --advisory=FEDORA-2026-7498616952

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: EaEa0001/servu-cve-2026-28318-poc (1 stars)
GitHub PoC: BishopFox/CVE-2026-28318-check (1 stars)

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-28318?

serv-u: upgrade to 15.5.4. Exact commands for each OS are on this page.

Is CVE-2026-28318 being exploited?

Yes. CVE-2026-28318 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-28318 affect?

CVE-2026-28318 affects serv-u. Severity is high (CVSS 7.5). 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

How urgent is CVE-2026-28318?

Priority 81/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Remotely exploitable, no login, no user action

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References

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