CVE-2026-41067Public exploitNetwork attack vector

Cross-site scripting via incomplete script-tag escaping

Published Apr 24, 2026 · Updated Apr 24, 2026

Cross-site scripting in Astro before 6.1.6 allows remote attackers to execute JavaScript in a victim's browser through SSR define:vars data. defineScriptVars serializes values and replaces only an exact lowercase closing script tag, leaving case, whitespace, and slash variants able to terminate the element. Exploitation requires an SSR application to pass request-derived data to define:vars and a victim to load the response, exposing that browser session to script actions.

CVSS severity6.1
Medium
EPSS probability0.19%
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 Astro before 6.1.6 allows remote attackers to execute JavaScript in a victim's browser through SSR define:vars data. defineScriptVars serializes values and replaces only an exact lowercase closing script tag, leaving case, whitespace, and slash variants able to terminate the element. Exploitation requires an SSR application to pass request-derived data to define:vars and a victim to load the response, exposing that browser session to script actions.

The record

CVE
CVE-2026-41067
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
Astro
Product
Astro
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 2026Record 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=< 6.1.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Astro · Astroversion=< 6.1.6

Published CVSS scores

6.1GitHub, Inc.CVSS: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.

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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
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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