ServiceStack before 5.9.2 mishandles JWT signature verification unless an application has…
Priority LOW 29CWE-347Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-347.
Summary
ServiceStack before 5.9.2 mishandles JWT signature verification unless an application has a custom ValidateToken function that establishes a valid minimum length for a signature.
Why it matters now
EPSS 0.02344 83rd percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Fixed ServiceStack (NuGet): 5.9.2
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | ServiceStack (NuGet) | before 5.9.2 | 5.9.2 | Patch available | GHSA-v5rv-hpxg-8x49 |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- ServiceStack (NuGet) Vendor— Affected before 5.9.2 Fixed in 5.9.2 Patch available GHSA-v5rv-hpxg-8x49
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:servicestack:servicestack:*:*:*:*:*:*:*:* | before 5.9.2 | Vulnerable | ServiceStack |
- cpe:2.3:a:servicestack:servicestack:*:*:*:*:*:*:*:* Versions before 5.9.2 Vulnerable ·ServiceStack
Remediation
- Fix · GHSA-v5rv-hpxg-8x49 ServiceStack (NuGet) Fixed in 5.9.2 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2020-28042
- 2026-10-03 Alias added: GHSA-v5rv-hpxg-8x49
References
Exploit 2
Advisory 2
More Servicestack vulnerabilities
- TI-2025-05846 Path traversal in ServiceStack CVSS 3.1HIGH 8.1
- TI-2019-16015 Cross-site scripting in ServiceStack Framework CVSS 3.0MEDIUM 6.1
- TI-2025-05845 Improper input validation in ServiceStack CVSS 3.1MEDIUM 5.9
Sources
- CVE-2020-28042 · CVE Program
- CVE-2020-28042 · NVD
- FIRST EPSS
- GHSA-v5rv-hpxg-8x49 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences