What is CVE-2026-28313?

CVE-2026-28313 is a critical-severity vulnerability in Solarwinds Serv-u, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 9.1/10. Published 2026-07-21.

How severe is CVE-2026-28313?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Auth bypass in Solarwinds Serv-u

CVE-2026-28313

SolarWinds Serv-U is affected by an insecure direct object reference (IDOR) vulnerability that can lead to SMTP hijacking leading to arbitrary account takeover. The impact is lower in Windows deployments.

Vulnerability class: IDOR (Insecure Direct Object Reference)

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

Affected products

Solarwinds Serv-u — versions 15.5.4 HF1 and below

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

psirt@solarwinds.com (vendor-advisory)
psirt@solarwinds.com (release-notes)

Frequently asked questions

What is CVE-2026-28313?: CVE-2026-28313 is a critical-severity vulnerability in Solarwinds Serv-u, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 9.1/10. Published 2026-07-21.
How severe is CVE-2026-28313?: Critical severity. CVSS v3 base score is 9.1 out of 10.