CVE-2026-45028CWE-323

Astro: Server island encrypted parameters vulnerable to cross-component replay

Low · published May 13, 2026

CVSS v4.0
2.9
EPSS
0%
Percentile
9.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
2.9 · LOW
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
EPSS
0.00198 · 9.1th percentile
Weakness
CWE-323 · Reusing a Nonce, Key Pair in Encryption
Published
2026-05-13T15:50Z
EPSS history
Timeline
  • 13 MAY 15:50Z
    Astro: Server island encrypted parameters vulnerable to cross-component replay
    cvelistv5