2.9
LOW CVSS 4.0
CVE-2026-45028
Astro: Server island encrypted parameters vulnerable to cross-component replay
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.

INFO

Published Date :

May 13, 2026, 4:17 p.m.

Last Modified :

May 13, 2026, 4:58 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-45028 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 LOW [email protected]
Solution
Update Astro to version 6.1.10 or later to fix a vulnerability allowing XSS attacks.
  • Update Astro to version 6.1.10 or later.
  • Ensure unique key names for props and slots.
  • Review component prop and slot values.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-45028.

URL Resource
https://github.com/withastro/astro/commit/3d82220a1549e699e34ed433f3846a919f4c02bd
https://github.com/withastro/astro/pull/16457
https://github.com/withastro/astro/security/advisories/GHSA-xr5h-phrj-8vxv
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-45028 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-45028 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-45028 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-45028 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    May. 13, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-323
    Added Reference https://github.com/withastro/astro/commit/3d82220a1549e699e34ed433f3846a919f4c02bd
    Added Reference https://github.com/withastro/astro/pull/16457
    Added Reference https://github.com/withastro/astro/security/advisories/GHSA-xr5h-phrj-8vxv
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.