Authentication Bypass in sogo_yhn
Summary
| CVE | CVE-2026-74864 |
|---|---|
| State | PUBLISHED |
| Assigner | CERT-PL |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-30 13:17:19 UTC |
| Updated | 2026-09-30 19:57:08 UTC |
| Description | sogo_yhn configures SOGo with a parameter that forces the request with HTTP header "x-webobjects-remote-user" to be treated as sent by a verified user without performing password validation. Since Nginx does not strip this header, any client can supply it arbitrarily and gain access as any user, including a privileged user, without providing a password. This issue was fixed in version 5.8.0~ynh9. |
Risk And Classification
Primary CVSS: v4.0 9.3 CRITICAL from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.005580000 probability, percentile 0.444720000 (date 2026-10-01)
Problem Types: CWE-639 | CWE-639 CWE-639 Authorization bypass through User-Controlled key
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 9.3 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 9.3 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | YunoHost-Apps | Sogo Yhn | affected 5.8.0~ynh9 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| forum.yunohost.org/t/sogo-critical-vulnerability-fixed-in-5-8-0-ynh9/42699 | [email protected] | forum.yunohost.org | |
| cert.pl/en/posts/2026/09/CVE-2026-74864 | [email protected] | cert.pl | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Przemysław Knycz WeKrwi.IT https://github.com/djrzulf (en)
There are currently no legacy QID mappings associated with this CVE.