CVE-2026-108860
BotSharp through 5.2.0 Authentication Bypass via Hard-Coded JWT Signing Key
- State
- Published
- Severity
- 9.3 Critical
- Published
- Oct 11, 2026
- Updated
- Oct 14, 2026
- Reserved
- Oct 11, 2026
Description
BotSharp through 5.2.0 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to forge bearer tokens using the hard-coded Jwt:Key in WebStarter appsettings.json. Attackers can sign tokens with the committed HMAC secret and fixed botsharp issuer and audience to impersonate any known user, including administrators, on Authorize-protected API routes.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 9.3 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | VulnCheck |
Weaknesses
- CWE-321 Use of Hard-coded Cryptographic Key
Affected Products
| Product | Versions |
|---|---|
BotSharpSciSharp |
|
References
- https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/scisharp-botsharp-public-jwt-signing-keythird-party-advisory
- https://github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/WebStarter/appsettings.json#L16-L20technical-description
- https://github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/Infrastructure/BotSharp.OpenAPI/BotSharpOpenApiExtensions.cs#L46-L57technical-description
- https://github.com/SciSharp/BotSharpproduct
- VulnCheck Advisory: BotSharp through 5.2.0 Authentication Bypass via Hard-Coded JWT Signing Keythird-party-advisory
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