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📦
📦 npm
Not in CISA KEV
CRITICAL severity

CVE-2022-0748 — post-loader

CRITICAL

CVE-2022-0748 is a critical-severity (CVSS 9.8) Cross-site Scripting (XSS) vulnerability in post-loader. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

Arbitrary Code Execution

Also known asGHSA-66ww-999q-mffqSNYK-JS-POSTLOADER-2403737
Published
Updated
Affected
1 pkg
Patched
See advisory
Exploits
1 known
Exploitation data as of Oct 28, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
2.1%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs82th percentile — riskier than 82% of all scored CVEsHighest risk
0.70%1.33%1.96%2.59%1.2%2.1%Apr 26Jul 26Oct 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

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

9other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
post-loadernpm
242downloads / week

Description

post-loader is webpack loader for blog posts written in Markdown. The package post-loader from 0.0.0 is vulnerable to Arbitrary Code Execution which uses a markdown parser in an unsafe way so that any javascript code inside the markdown input files gets evaluated and executed. At this time, there is no known workaround or patch available.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
📦npmpost-loader≥ 0.0.0No fix

Affected Products

1 product · 1 configurations
Application
post-loaderpost-loader_project
≤ 2.0.0
range
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.

The package post-loader from 0.0.0 are vulnerable to Arbitrary Code Exec…

snyk.ioNVDMar 2022

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for post-loader, 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 post-loader for CVE-2022-0748. 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

    Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

post-loader is webpack loader for blog posts written in Markdown. The package post-loader from 0.0.0 is vulnerable to Arbitrary Code Execution which uses a markdown parser in an unsafe way so that any javascript code inside the markdown input files gets evaluated and executed. At this time, there is no known workaround or patch available.
O3 Security · Impact-Aware SCA

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CVE-2022-0748: post-loader: Arbitrary Code Execution