CVE-2025-55166Public exploitNetwork attack vector

Cross-site scripting via mixed-case href attributes

Published Aug 12, 2025 · Updated Aug 12, 2025

Cross-site scripting in Daryll Doyle SVG Sanitizer before 0.22.0 allows remote attackers to inject unsafe links via crafted SVG input. The cleanXlinkHrefs method looks up only lowercase xlink:href names, so mixed-case variants bypass isHrefSafeValue and survive sanitization. Exploitation requires a consuming application to render the sanitized SVG and a user to activate the malicious link, enabling script execution or navigation to an external domain.

CVSS severity5.1
Medium
EPSS probability0.45%
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 Daryll Doyle SVG Sanitizer before 0.22.0 allows remote attackers to inject unsafe links via crafted SVG input. The cleanXlinkHrefs method looks up only lowercase xlink:href names, so mixed-case variants bypass isHrefSafeValue and survive sanitization. Exploitation requires a consuming application to render the sanitized SVG and a user to activate the malicious link, enabling script execution or navigation to an external domain.

The record

CVE
CVE-2025-55166
Published
Aug 12, 2025
Updated
Aug 12, 2025
Vendor
Daryll Doyle
Product
SVG Sanitizer
Classifications
CWE-79, CWE-601, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 12, 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=< 0.22.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Daryll Doyle · SVG Sanitizerversion=< 0.22.0

Published CVSS scores

5.1GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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')
CWE-601URL Redirection to Untrusted Site ('Open Redirect')
T1204.002Malicious File

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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