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.NET
.NET NuGet
Not in CISA KEV
HIGH severity

CVE-2018-15121 — Auth0-ASPNET-Owin

HIGH

CVE-2018-15121 is a high-severity (CVSS 8.8) Cross-Site Request Forgery (CSRF) vulnerability in Auth0-ASPNET-Owin. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

Auth0-ASPNET and Auth0-ASPNET-Owin vulnerable to Cross-Site Request Forgery

Published
Updated
Affected
2 pkgs
Patched
See advisory
Exploits
None indexed
Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.5%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs42th percentile — riskier than 42% of all scored CVEsHighest risk
0.00%0.33%0.66%0.99%0.1%0.5%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected
.NETAuth0-ASPNET-Owin.NETauth0-aspnet

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

An issue was discovered in Auth0 auth0-aspnet and auth0-aspnet-owin. Affected packages do not use or validate the state parameter of the OAuth 2.0 and OpenID Connect protocols. This leaves applications vulnerable to CSRF attacks during authentication and authorization operations.

Affected Packages

2 total
EcosystemPackageVulnerable rangeFix
.NETNuGetAuth0-ASPNET-Owinall versionsNo fix
.NETNuGetauth0-aspnetall versionsNo fix

Affected Products

2 products · 2 configurations
Application
aspnetauth0
all
Application
aspnet-owinauth0
all

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Auth0-ASPNET-Owin, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    The records we use list no patched version of Auth0-ASPNET-Owin for CVE-2018-15121. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

An issue was discovered in Auth0 auth0-aspnet and auth0-aspnet-owin. Affected packages do not use or validate the state parameter of the OAuth 2.0 and OpenID Connect protocols. This leaves applications vulnerable to CSRF attacks during authentication and authorization operations.
O3 Security · Impact-Aware SCA

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CVE-2018-15121: Auth0-ASPNET-Owin CSRF (High 8.8)