CVE-2025-46734Public exploitNetwork attack vector

Script execution via unfiltered Markdown attributes

Published May 5, 2025 · Updated May 6, 2025

Cross-site scripting in CommonMark 1.5.0 through 2.6.x allows remote authenticated users to execute JavaScript via crafted Markdown. AttributesListener copies curly-brace attributes to rendered elements without rejecting event handlers or unsafe href and src values. Exploitation requires AttributesExtension to process untrusted Markdown; injected script runs in the rendered page's browser context.

CVSS severity6.4
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in CommonMark 1.5.0 through 2.6.x allows remote authenticated users to execute JavaScript via crafted Markdown. AttributesListener copies curly-brace attributes to rendered elements without rejecting event handlers or unsafe href and src values. Exploitation requires AttributesExtension to process untrusted Markdown; injected script runs in the rendered page's browser context.

The record

CVE
CVE-2025-46734
Published
May 5, 2025
Updated
May 6, 2025
Vendor
The PHP League
Product
CommonMark
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 5, 2025CVE publishedPublication date reported by the CVE source.
  2. May 6, 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=< 2.7.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The PHP League · CommonMarkversion=< 2.7.0

Published CVSS scores

6.4GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

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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