CVE-2024-53986Network attack vector

Cross-site scripting via foreign-content namespace confusion

Published Dec 2, 2024 · Updated Dec 3, 2024

Cross-site scripting in Rails rails-html-sanitizer 1.6.0 allows remote attackers to inject active content through crafted HTML. SafeListSanitizer strips disallowed MathML nodes by promoting their children, allowing namespace confusion and DOM mutation to expose an event handler after browser reparsing. Exploitation requires Rails 7.1.0 or later, HTML5 sanitization, an allowlist containing both math and style, attacker-controlled HTML, and a user who renders the sanitized result.

CVSS severity2.3
Low
EPSS probability0.47%
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 Rails rails-html-sanitizer 1.6.0 allows remote attackers to inject active content through crafted HTML. SafeListSanitizer strips disallowed MathML nodes by promoting their children, allowing namespace confusion and DOM mutation to expose an event handler after browser reparsing. Exploitation requires Rails 7.1.0 or later, HTML5 sanitization, an allowlist containing both math and style, attacker-controlled HTML, and a user who renders the sanitized result.

The record

CVE
CVE-2024-53986
Published
Dec 2, 2024
Updated
Dec 3, 2024
Vendor
Rails
Product
rails-html-sanitizer
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 2, 2024CVE publishedPublication date reported by the CVE source.
  2. Dec 3, 2024Record 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=>= 1.6.0, < 1.6.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rails · rails-html-sanitizerversion=>= 1.6.0, < 1.6.1

Published CVSS scores

2.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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 exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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