Vulnerability · Published May 13, 2026 · Assigned by GitHub_M
CVE-2026-45028Astro: Server island encrypted parameters vulnerable to cross-component replay
Low 2.9
In plain English
A low-severity security flaw in astro from withastro. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | astro | 6.1.10 | GHSA-xr5h-phrj-8vxv |
Affected products (as reported)
Weakness: CWE-323 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
References
- https://github.com/withastro/astro/security/advisories/GHSA-xr5h-phrj-8vxv x_refsource_CONFIRM
- https://github.com/withastro/astro/pull/16457 x_refsource_MISC
- https://github.com/withastro/astro/commit/3d82220a1549e699e34ed433f3846a919f4c02bd x_refsource_MISC