What’s Vulnerable › Vulnerabilities

CVE-2026-111633: ZKEACMS through 4.4 Authentication Bypass via Hard-Coded JWT Signing Key

• Severity: high (CVSS 8.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-16 · updated 2026-10-23
• Weakness: CWE-321

Description

ZKEACMS through 4.4 contains an authentication bypass vulnerability that allows unauthenticated attackers to forge REST API JWT bearer tokens using a hard-coded HMAC-SHA256 signing key in JwtBearerDefaults.cs. Attackers can sign a token with the Name claim set to 'admin' to call ApiAuthorize endpoints, modifying articles and products and reading form submissions.

Affected products

• SeriaWei ZKEACMS: through 4.4

References

• https://github.com/SeriaWei/ZKEACMS/blob/v4.4/src/ZKEACMS/Api/JwtBearerDefaults.cs#L14-L19
• https://github.com/SeriaWei/ZKEACMS/blob/v4.4/src/ZKEACMS/BuilderAuthentication.cs#L41-L52
• https://github.com/SeriaWei/ZKEACMS/issues/531
• https://hackmd.io/@hieuPenguinnn/zkeacms-hardcoded-jwt-signing-key-admin-auth-bypass
• https://www.vulncheck.com/advisories/zkeacms-through-4.4-authentication-bypass-via-hard-coded-jwt-signing-key
• https://github.com/SeriaWei/ZKEACMS/issues/531
• https://hackmd.io/@hieuPenguinnn/zkeacms-hardcoded-jwt-signing-key-admin-auth-bypass

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