EUVD Vulnerability Catalog
EUVD-2026-97011
Severity: CRITICAL
Base Score: 9.3
CVSS Version: 4.0
Vulnerability 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.
CVSS Vector Analysis
Below is the complete, human-readable breakdown of the CVSS metric string: 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
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Attack Vector (AV): Network
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Attack Complexity (AC): Low
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Attack Requirements (AT): None
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Privileges Required (PR): None
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User Interaction (UI): None
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Vulnerability Confidentiality Impact (VC): High
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Vulnerability Integrity Impact (VI): High
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Vulnerability Availability Impact (VA): None
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Subsequent Confidentiality Impact (SC): None
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Subsequent Integrity Impact (SI): None
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Subsequent Availability Impact (SA): None
Affected Vendors & Systems
Vendor
SciSharp
References & Advisory Links
- https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/scisharp-botsharp-public-jwt-signing-key
- https://github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/WebStarter/appsettings.json#L16-L20
- https://github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/Infrastructure/BotSharp.OpenAPI/BotSharpOpenApiExtensions.cs#L46-L57
- https://github.com/SciSharp/BotSharp
- https://www.vulncheck.com/advisories/botsharp-through-5.2.0-authentication-bypass-via-hard-coded-jwt-signing-key
Metadata Profile
Database Authority
European Union Agency for Cybersecurity (ENISA) EUVD
Assigner
VulnCheck
EPSS Probability
0
Known Aliases
CVE-2026-108860
Published On
2026-10-11
Last Updated
2026-10-11