How severe is CVE-2026-45028?

CVE-2026-45028 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-45028 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-45028?

CVE-2026-45028 affects Astro. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-45028?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-45028 have an EU (EUVD) identifier?

Yes. CVE-2026-45028 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30054.

When was CVE-2026-45028 published?

CVE-2026-45028 was published on 2026-05-13 and last updated on 2026-06-17.

CVE-2026-45028

CVE-2026-45028 is a medium-severity vulnerability in Astro with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v4: 2.9
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30054
Weakness: CWE-79
Affected product: Astro
Published: 2026-05-13
Last modified: 2026-06-17

Description

Astro is a web framework. Astro versions prior to 6.1.10 used AES-GCM encryption to protect the confidentiality and integrity of server island props and slots parameters, but did not bind the ciphertext to its intended component or parameter type. An attacker could replay one component's encrypted props (p) value as another component's slots (s) value, or vice versa. Since slots contain raw unescaped HTML while props may contain user-controlled values, this could lead to XSS in applications. This occurs when the application uses server islands, two different server island components share the same key name for a prop and a slot, and an attacker has full control over the value of the overlapping prop (requires a dynamically rendered page). This vulnerability is fixed in 6.1.10.

Frequently asked questions

What is CVE-2026-45028?: Astro is a web framework. Astro versions prior to 6.1.10 used AES-GCM encryption to protect the confidentiality and integrity of server island props and slots parameters, but did not bind the ciphertext to its intended component or parameter type. An attacker could replay one component's encrypted props (p) value as another component's slots (s) value, or vice versa. Since slots contain raw unescaped HTML while props may contain user-controlled values, this could lead to XSS in applications. This occurs when the application uses server islands, two different server island components share the same key name for a prop and a slot, and an attacker has full control over the value of the overlapping prop (requires a dynamically rendered page). This vulnerability is fixed in 6.1.10.
How severe is CVE-2026-45028?: CVE-2026-45028 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-45028 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-45028?: CVE-2026-45028 affects Astro. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-45028?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-45028 have an EU (EUVD) identifier?: Yes. CVE-2026-45028 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30054.
When was CVE-2026-45028 published?: CVE-2026-45028 was published on 2026-05-13 and last updated on 2026-06-17.

References

Affected products (1)

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

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