CVE-2026-108860 (CVSS 9.1)

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.

Is your site exposed to CVE-2026-108860?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0048

Probability of exploitation

0.40%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-321 CWE-321

References

Other References

https://github.com/SciSharp/BotSharp https://github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/Infrastructure/BotSharp.OpenAPI/BotSharpOpenApiExtensions.cs#L46-L57 https://github.com/SciSharp/BotSharp/blob/a11ee0317cab5c619df1cb5d0c4fc39d1b6e30b4/src/WebStarter/appsettings.json#L16-L20 https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/scisharp-botsharp-public-jwt-signing-key https://www.vulncheck.com/advisories/botsharp-through-5.2.0-authentication-bypass-via-hard-coded-jwt-signing-key

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-108860? +

CVE-2026-108860 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0048, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-108860? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-11347

The linqi application contains hardcoded cryptographic keys. Additionally, the application uses a weak algorithm with a limited ASCII charset to …

CVE-2026-34022

The Wertheim SafeController Family 65000, Controller 65000 - AssemblyVersion 6.11.8130.22319, uses weak custom cryptographic algorithms with hard-coded cryptographic keys to …

CVE-2026-34029

The Wertheim SafeController Software, AssemblyVersion 6.15.8328.28014, contains a hard-coded cryptographic key in the SafeSystem.Infrastructure.Security.dll component. An attacker with access to …

CVE-2026-45433

This vulnerability exists in GX Earth 2022 ONT models due to the presence of hardcoded RSA private key within the …

CVE-2025-1099

This vulnerability exists in Tapo C500 Wi-Fi camera due to hard-coded RSA private key embedded within the device firmware. An …

CVE-2025-34500

Deck Mate 2's firmware update mechanism accepts packages without cryptographic signature verification, encrypts them with a single hard-coded AES key …

CVE-2026-108860