How severe is CVE-2023-36558?

CVE-2023-36558 has a CVSS score of 5.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-36558?

CVE-2023-36558 affects the following packages: Microsoft.AspNetCore.Components (NuGet), Microsoft.AspNetCore.Components (NuGet), Microsoft.AspNetCore.Components (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2023-36558?

Update Microsoft.AspNetCore.Components to 8.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-36558 is resolved across your whole dependency graph.

How do I detect CVE-2023-36558 in my NuGet dependencies?

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

How do I mitigate CVE-2023-36558 if there is no patch (or I can't update yet)?

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.

How does O3 Security protect against CVE-2023-36558?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-36558 can be triaged on real exposure rather than presence alone.

Is CVE-2023-36558 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-36558 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-36558?

CVE-2023-36558 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 64th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2023-36558 published, and has it been updated?

CVE-2023-36558 was published on November 14, 2023 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET

.NET NuGet

Not in CISA KEV

MEDIUM severity

CVE-2023-36558 — Microsoft.AspNetCore.Comp…

MEDIUM

CVE-2023-36558 is a medium-severity (CVSS 5.5) vulnerability in Microsoft.AspNetCore.Components. A fix is available for Microsoft.AspNetCore.Components — see the affected versions and patch details below.

Microsoft Security Advisory CVE-2023-36558: .NET Security Feature Bypass Vulnerability

Also known asBIT-aspnet-core-2023-36558BIT-dotnet-2023-36558BIT-dotnet-sdk-2023-36558GHSA-3fx3-85r4-8j3w

Published

Nov 14, 2023

Updated

Jul 8, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-36558.

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs64th percentile — riskier than 64% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2023-36558 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

3 pkgs affected

.NETMicrosoft.AspNetCore.Components.NETMicrosoft.AspNetCore.Components.NETMicrosoft.AspNetCore.Components

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

ASP.NET Core Security Feature Bypass Vulnerability

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Microsoft.AspNetCore.Components`	≥ 8.0.0-rc.2.23480.2&&< 8.0.0	8.0.0`dotnet add package Microsoft.AspNetCore.Components --version 8.0.0`
.NETNuGet	`Microsoft.AspNetCore.Components`	≥ 7.0.0&&< 7.0.14	7.0.14`dotnet add package Microsoft.AspNetCore.Components --version 7.0.14`
.NETNuGet	`Microsoft.AspNetCore.Components`	≥ 6.0.0&&< 6.0.25	6.0.25`dotnet add package Microsoft.AspNetCore.Components --version 6.0.25`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.AspNetCore.Components, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.AspNetCore.Components to 8.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-36558 is resolved across your whole dependency graph.
Workarounds
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-36558 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2023-36558. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Product	Fixed in	Advisory
.NET Core on Red Hat Enterprise Linux	`rh-dotnet60-dotnet-0:6.0.125-1.el7_9`	RHSA-2023:7259
Red Hat Enterprise Linux 8	`dotnet8.0-0:8.0.100-2.el8_9`	RHSA-2023:7254
Red Hat Enterprise Linux 8	`dotnet7.0-0:7.0.114-1.el8_9`	RHSA-2023:7256
Red Hat Enterprise Linux 8	`dotnet6.0-0:6.0.125-1.el8_9`	RHSA-2023:7258
Red Hat Enterprise Linux 9	`dotnet8.0-0:8.0.100-2.el9_3`	RHSA-2023:7253
Red Hat Enterprise Linux 9	`dotnet7.0-0:7.0.114-1.el9_3`	RHSA-2023:7255
Red Hat Enterprise Linux 9	`dotnet6.0-0:6.0.125-1.el9_3`	RHSA-2023:7257

UbuntuMEDIUM

USN-6480-1Ubuntu

Frequently Asked Questions

ASP.NET Core Security Feature Bypass Vulnerability

O3 Security · Impact-Aware SCA

Is CVE-2023-36558 in your dependencies?

O3 Security finds CVE-2023-36558 across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works