How severe is CVE-2026-54299?

CVE-2026-54299 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2026-54299 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-54299?

CVE-2026-54299 affects Astro. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-54299?

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-2026-54299 have an EU (EUVD) identifier?

Yes. CVE-2026-54299 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38337.

When was CVE-2026-54299 published?

CVE-2026-54299 was published on 2026-06-22 and last updated on 2026-06-23.

CVE-2026-54299

CVE-2026-54299 is a high-severity vulnerability in Astro with a CVSS 3.x base score of 7.5. 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (10th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-38337
Weakness: CWE-20
Affected product: Astro
Published: 2026-06-22
Last modified: 2026-06-23

Description

Astro is a web framework. Prior to 6.4.6, Astro SSR apps with prerendered error pages (/404 or /500 using export const prerender = true) fetch those pages over HTTP at runtime when an error occurs. The URL for this fetch is derived from request.url, which in turn gets its origin from the incoming Host header. When the Host header is not validated against allowedDomains, an attacker can point the fetch at an arbitrary host and read the response. This vulnerability is fixed in 6.4.6.

Frequently asked questions

What is CVE-2026-54299?: Astro is a web framework. Prior to 6.4.6, Astro SSR apps with prerendered error pages (/404 or /500 using export const prerender = true) fetch those pages over HTTP at runtime when an error occurs. The URL for this fetch is derived from request.url, which in turn gets its origin from the incoming Host header. When the Host header is not validated against allowedDomains, an attacker can point the fetch at an arbitrary host and read the response. This vulnerability is fixed in 6.4.6.
How severe is CVE-2026-54299?: CVE-2026-54299 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2026-54299 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-54299?: CVE-2026-54299 affects Astro. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-54299?: 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-2026-54299 have an EU (EUVD) identifier?: Yes. CVE-2026-54299 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38337.
When was CVE-2026-54299 published?: CVE-2026-54299 was published on 2026-06-22 and last updated on 2026-06-23.

References

https://github.com/withastro/astro/security/advisories/GHSA-2pvr-wf23-7pc7

Affected products (1)

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

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