How severe is CVE-2026-50146?

CVE-2026-50146 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity high, and availability none.

Is CVE-2026-50146 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-50146?

CVE-2026-50146 affects Astro. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-50146?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-50146 have an EU (EUVD) identifier?

Yes. CVE-2026-50146 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38335.

When was CVE-2026-50146 published?

CVE-2026-50146 was published on 2026-06-22 and last updated on 2026-06-23.

CVE-2026-50146

CVE-2026-50146 is a high-severity vulnerability in Astro with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-80.

Key facts

Severity: High (CVSS 3.x base score 7.1)
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-38335
Weakness: CWE-80
Affected product: Astro
Published: 2026-06-22
Last modified: 2026-06-23

Description

Astro is a web framework. Prior to 6.3.3, when a component uses a client:* directive, Astro inserts named slot content into a data-astro-template attribute without HTML escaping the slot name allowing an attacker to break out of the attribute context and inject arbitrary HTML, resulting in reflected XSS during SSR. This vulnerability is fixed in 6.3.3.

Frequently asked questions

What is CVE-2026-50146?: Astro is a web framework. Prior to 6.3.3, when a component uses a client:* directive, Astro inserts named slot content into a data-astro-template attribute without HTML escaping the slot name allowing an attacker to break out of the attribute context and inject arbitrary HTML, resulting in reflected XSS during SSR. This vulnerability is fixed in 6.3.3.
How severe is CVE-2026-50146?: CVE-2026-50146 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity high, and availability none.
Is CVE-2026-50146 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-50146?: CVE-2026-50146 affects Astro. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-50146?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-50146 have an EU (EUVD) identifier?: Yes. CVE-2026-50146 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38335.
When was CVE-2026-50146 published?: CVE-2026-50146 was published on 2026-06-22 and last updated on 2026-06-23.

References

https://github.com/withastro/astro/security/advisories/GHSA-8hv8-536x-4wqp

Affected products (1)

cpe:2.3:a:astro:astro:*:*:*:*:*:node.js:*:*

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