Exploited

CVE-2026-28318

SolarWinds Serv-U · Managed file transfer (MFT)

SolarWinds Serv-U Uncontrolled Resource Consumption Vulnerability

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on June 5, 2026.

Affected product: SolarWinds Serv-U (category Managed file transfer (MFT), indicative classification). Name in CISA’s catalog: SolarWinds Serv-U.

What should I do?

Apply the patches or mitigations from SolarWinds; if none are available, stop using the product. For cloud services, follow the guidance from SolarWinds.

Deadline set by CISA for US federal agencies: 14 days (due June 19, 2026). It only binds those agencies, but it is a useful measure of urgency.

SolarWinds security advisories page (general page, not the advisory for this vulnerability)
The vendor’s specific advisory is listed in the NVD references: CVE-2026-28318 on the NVD website.

Original text of the required action (CISA)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Timeline

June 4, 2026 Vulnerability published Publication date (NVD)
June 5, 2026 Exploitation confirmed Added to CISA’s KEV catalog
June 19, 2026 CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed: Yes, on June 5, 2026 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Ransomware: No known use to date That does not guarantee it is not being used: the information is not public. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Hunt for compromise: Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA required action: Apply the patches or mitigations from SolarWinds; if none are available, stop using the product. For cloud services, follow the guidance from SolarWinds. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA deadline: June 19, 2026, 14 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Vulnerability published: June 4, 2026 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Product according to CISA: SolarWinds Serv-U Filed by this site under “Managed file transfer (MFT)” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC

Severity and activity

7.5 / 10 CVSS severity: high

Score from the vendor or CISA, relayed by the NVD. Collected Sep 29, 2026.

— Probability of exploitation in the next 30 days (EPSS)

FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.

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

SolarWinds Serv-U contains an uncontrolled resource consumption vulnerability that allows specially crafted POST requests using the Content-Encoding: deflate header to crash the Serv-U service without authentication.

Summary from CISA (KEV catalog).

CERT-FR advisories

No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.

Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.

Sources for this page

CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
NVD (NIST): CVSS severity, publication date, description, vendor references.
EPSS (FIRST): probability of exploitation.
CERT-FR: advisories and alerts (in French).
Brand and category: indicative classification by this site (method).