CVE-2017-9785
Deserialization of Untrusted Data in NancyFX Nancy
Csrf.cs in NancyFX Nancy before 1.4.4 and 2.x before 2.0-dangermouse has Remote Code Execution via Deserialization of JSON data in a CSRF Cookie.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
Csrf.cs in NancyFX Nancy before 1.4.4 and 2.x before 2.0-dangermouse has Remote Code Execution via Deserialization of JSON data in a CSRF Cookie.
- Record
CVE-2017-9785- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-502
- Updated
- 2026-11-02
CVE List No score
Csrf.cs in NancyFX Nancy before 1.4.4 and 2.x before 2.0-dangermouse has Remote Code Execution via Deserialization of JSON data in a CSRF Cookie.
- Record
CVE-2017-9785- Updated
- 2026-11-02
EUVDEUVD-2022-4645 No score
Csrf.cs in NancyFX Nancy before 1.4.4 and 2.x before 2.0-dangermouse has Remote Code Execution via Deserialization of JSON data in a CSRF Cookie.
- Record
EUVD-2022-4645- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-mx3q-j2g2-5qxq
Deserialization of Untrusted Data in NancyFX Nancy
Csrf.cs in NancyFX Nancy before 1.4.4 and 2.x before 2.0-dangermouse has Remote Code Execution via Deserialization of JSON data in a CSRF Cookie.
- Record
GHSA-mx3q-j2g2-5qxq- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
OSV
Csrf.cs in NancyFX Nancy before 1.4.4 and 2.x before 2.0-dangermouse has Remote Code Execution via Deserialization of JSON data in a CSRF Cookie.
- Record
CVE-2017-9785- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-mx3q-j2g2-5qxq
Deserialization of Untrusted Data in NancyFX Nancy
Csrf.cs in NancyFX Nancy before 1.4.4 and 2.x before 2.0-dangermouse has Remote Code Execution via Deserialization of JSON data in a CSRF Cookie.
- Record
GHSA-mx3q-j2g2-5qxq- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
NancyNuGet |
through 1.4.3 | 1.4.4 |
NancyNuGet |
2.0.0-alpha to 2.0.0-clinteastwood | 2.0.0 |
NancyNuGet |
before 1.4.4, plus listed versions 0.10.00.11.00.12.00.12.10.13.0 Show 36 moreShow less0.14.00.14.10.15.00.15.10.15.20.15.30.16.00.16.10.17.00.17.10.18.00.20.00.21.00.21.10.22.00.22.10.22.20.23.00.23.10.23.20.4.00.5.00.6.00.7.00.7.10.8.00.8.10.9.01.0.01.1.01.2.01.3.01.4.01.4.11.4.21.4.3 |
1.4.4 |
NancyNuGet |
2.0.0-alpha up to 2.0.0, plus listed versions 2.0.0-barneyrubble2.0.0-clienteastwood2.0.0-clinteastwood |
2.0.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2017-9785 is a critical vulnerability (CVSS 9.8) in Nancyfx Nancy, published July 20, 2017. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.01%, the 87th percentile. Fixed in Nancy 1.4.4.