CVE-2023-1767Public exploitNetwork attack vector

Stored XSS via unsanitized package README rendering

Published Apr 20, 2023 · Updated Feb 5, 2025

Stored XSS in Snyk Advisor before 2023-03-28 allows remote attackers to execute JavaScript when users view an imported package page. The service converted an imported npm package's Markdown README to HTML without sanitization or a blocking content security policy. Exploitation requires a victim to visit the package-health page after ingestion; the demonstrated script rewrites displayed health information.

CVSS severity4.3
Medium
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Snyk Advisor before 2023-03-28 allows remote attackers to execute JavaScript when users view an imported package page. The service converted an imported npm package's Markdown README to HTML without sanitization or a blocking content security policy. Exploitation requires a victim to visit the package-health page after ingestion; the demonstrated script rewrites displayed health information.

The record

CVE
CVE-2023-1767
Published
Apr 20, 2023
Updated
Feb 5, 2025
Vendor
Snyk
Product
Snyk Advisor
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 20, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 5, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2020-10-01 <2023-03-28

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Snyk · Snyk Advisorversion=2020-10-01 <2023-03-28

Published CVSS scores

4.3SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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