---
id: CVE-2026-108860
title: >-
  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
summary: >-
  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 co…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-321
published: '2026-10-11'
updated: '2026-10-11'
sourceUpdated: '2026-10-11T14:17:05.933'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-108860'
references:
  - url: 'https://github.com/SciSharp/BotSharp'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/Infrastructure/BotSharp.OpenAPI/BotSharpOpenApiExtensions.cs#L46-L57
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/WebStarter/appsettings.json#L16-L20
    label: disclosure@vulncheck.com
  - url: >-
      https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/scisharp-botsharp-public-jwt-signing-key
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/botsharp-through-5.2.0-authentication-bypass-via-hard-coded-jwt-signing-key
    label: disclosure@vulncheck.com
tags:
  - nvd
ingestedAt: '2026-10-12T14:50:34.053Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.