CVE-2025-29771Network attack vector

Cross-site scripting via post-sanitization beautifier

Published Mar 14, 2025 · Updated Mar 18, 2025

Cross-site scripting in Jitbit HtmlSanitizer before 2.0.3 allows remote attackers to execute JavaScript via crafted HTML. The sanitizer serializes a safe DOM to resultElement.innerHTML and then applies a regex-based br beautifier, allowing crafted output to become executable markup after sanitization. The flaw is reachable only when a consuming application assigns the result to a contentEditable element's innerHTML, exposing that page's origin to injected script.

CVSS severity6.9
Medium
EPSS probability0.40%
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 Jitbit HtmlSanitizer before 2.0.3 allows remote attackers to execute JavaScript via crafted HTML. The sanitizer serializes a safe DOM to resultElement.innerHTML and then applies a regex-based br beautifier, allowing crafted output to become executable markup after sanitization. The flaw is reachable only when a consuming application assigns the result to a contentEditable element's innerHTML, exposing that page's origin to injected script.

The record

CVE
CVE-2025-29771
Published
Mar 14, 2025
Updated
Mar 18, 2025
Vendor
Michael Ganss
Product
HtmlSanitizer
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 14, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 18, 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=< 2.0.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Michael Ganss · HtmlSanitizerversion=< 2.0.3

Published CVSS scores

6.9GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA: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')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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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