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.NET
.NET NuGet
Not in CISA KEV
HIGH severity

CVE-2015-8813 Umbraco.CMS

HIGHFix: umbraco/Umbraco-CMS@924a016

CVE-2015-8813 is a high-severity (CVSS 8.2) Server-Side Request Forgery (SSRF) vulnerability in Umbraco.CMS. 1 public exploit reference exists, so weaponization risk is real. A fix is available for Umbraco.CMS — see the affected versions and patch details below.

Umbraco CMS vulnerable to CSRF

Published
May 17, 2022
Updated
Nov 8, 2023
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
11.2%probability of exploitation in next 30 days
Moderate Risk0.00%
Lower risk than most CVEs96th percentile — riskier than 96% 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-2015-8813 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 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
.NETUmbraco.CMS

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

The Page_Load function in Umbraco.Web/umbraco.presentation/umbraco/dashboard/FeedProxy.aspx.cs in Umbraco before 7.4.0 allows remote attackers to conduct server-side request forgery (SSRF) attacks via the url parameter.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetUmbraco.CMSall versions7.4.0dotnet add package Umbraco.CMS --version 7.4.0
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Detection & mitigation playbook

Open-source dependency
  1. Detect

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

  2. Fix

    Update Umbraco.CMS to 7.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2015-8813 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2015-8813 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2015-8813. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

How to detect CVE-2015-8813

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id cve-2015-8813 -u https://target
Template
Umbraco <7.4.0- Server-Side Request Forgery
Severity
high
Impact
The vulnerability can result in unauthorized access to sensitive information or systems, leading to potential data breaches or further exploitation.
Remediation
Upgrade Umbraco to version 7.4.0 or above to mitigate the vulnerability and apply any necessary patches or security updates.

Template by ProjectDiscovery nuclei-templates (emadshanab), MIT licensed. View the full template. Scan only systems you are authorised to test.

Frequently Asked Questions

The `Page_Load` function in [Umbraco.Web/umbraco.presentation/umbraco/dashboard/FeedProxy.aspx.cs](https://github.com/umbraco/Umbraco-CMS/commit/924a016ffe7ae7ea6d516c07a7852f0095eddbce#diff-2899f01df84571577834f97a81637c65e20178ec6129b76c02f99789b23cf72e) in Umbraco before 7.4.0 allows remote attackers to conduct server-side request forgery (SSRF) attacks via the url parameter.
O3 Security · Impact-Aware SCA

Is CVE-2015-8813 in your dependencies?

O3 Security finds CVE-2015-8813 across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2015-8813: Umbraco.CMS (High 8.2) | O3 Security