CVE-2026-34403 json
Nginx-UI vulnerable to Cross-Site WebSocket Hijacking (CSWSH) via missing origin validation on all WebSocket endpoints
published 2026-04-20 6 mo ago modified 2026-10-26 13 d ago also GHSA-78mf-482w-62qj , GO-2026-5210 , EUVD-2026-23972
- cvss
- 8.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- public exploits
- 0
- none known
Summary
Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.5, all WebSocket endpoints in nginx-ui use a gorilla/websocket Upgrader with CheckOrigin unconditionally returning true, allowing Cross-Site WebSocket Hijacking (CSWSH). Combined with the fact that authentication tokens are stored in browser cookies (set via JavaScript without HttpOnly or explicit SameSite attributes), a malicious webpage can establish authenticated WebSocket connections to the nginx-ui instance when a logged-in administrator visits the attacker-controlled page. Version 2.3.5 patches the issue.
Patch / fix
- go github.com/0xJacky/Nginx-UI 1.9.10-0.20260316053337-1a9cd29a3082
- nginxui nginx_ui 2.3.5
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.5 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P |
| CNA | 4.0 | 5.5 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/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 |
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N |
| GitHub | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/0xJacky/Nginx-UI | <1.9.10-0.20260316053337-1a9cd29a3082 |
1.9.10-0.20260316053337-1a9cd29a3082 |
Affected products
- 0xJacky nginx-ui
Classification
References
-
github.com
/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj
web, exploit, mitigation, vendor-advisory, advisory
-
github.com
/0xJacky/nginx-ui/releases/tag/v2.3.5
web, product, release-notes
-
nvd.nist.gov
/vuln/detail/CVE-2026-34403
advisory
-
github.com
/0xJacky/nginx-ui
package
Sources
- CVE List CVE-2026-34403
- GitHub Advisory GHSA-78mf-482w-62qj
- NVD CVE-2026-34403
- OSV GO-2026-5210
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