Vulnerability · Published Jul 21, 2026 · Assigned by SolarWinds
CVE-2026-28313SolarWinds Serv-U Insecure Direct Object Reference (IDOR) Vulnerability
Critical 9.1
In plain English
A critical-severity authorization bypass via user-controlled key in Serv-U from SolarWinds. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities).
Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.5%top 57.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| SolarWinds | Serv-U | 15.5.4 HF1 and below |
Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H