CVE-2026-73422Public exploitNetwork attack vector

Reflected XSS via unescaped transition animation values

Published Aug 12, 2026 · Updated Aug 12, 2026

Cross-site scripting in Astro 2.9.0 through 7.0.9 allows remote attackers to execute JavaScript via crafted transition values. The server-side View Transition generator passes serialized animation properties into a raw style element without CSS or HTML escaping, so a duration value can close the element and inject markup. Exploitation requires a server-rendered route to place attacker-controlled data in an animation definition and grants access to page data and victim-authorized actions.

CVSS severity5.3
Medium
EPSS probability0.39%
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 2.9.0 through 7.0.9 allows remote attackers to execute JavaScript via crafted transition values. The server-side View Transition generator passes serialized animation properties into a raw style element without CSS or HTML escaping, so a duration value can close the element and inject markup. Exploitation requires a server-rendered route to place attacker-controlled data in an animation definition and grants access to page data and victim-authorized actions.

The record

CVE
CVE-2026-73422
Published
Aug 12, 2026
Updated
Aug 12, 2026
Vendor
Astro Technology Company
Product
Astro
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2.9.0, < 7.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Astro Technology Company · Astroversion=>= 2.9.0, < 7.1.0

Published CVSS scores

5.3GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
8.1Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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 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')
T1203Exploitation for Client Execution

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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