Vulnerability in Scisharp Botsharp
CVE-2026-108860
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.
Published .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/scisharp-botsharp-public-jwt-signing-key (third-party-advisory)
- github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/… (technical-description)
- github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/… (technical-description)
- github.com/SciSharp/BotSharp (product)
- www.vulncheck.com/advisories/botsharp-through-5.2.0-authentication-bypass-via-h… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-108860?
- CVE-2026-108860 is a critical-severity vulnerability in Scisharp Botsharp, classified under Use of Hard-coded Cryptographic Key. CVSS score: 9.1/10. Published 2026-10-11.
- How severe is CVE-2026-108860?
- Critical severity. CVSS v3 base score is 9.1 out of 10.