VulnerabilityAnalyzed

CVE-2026-45028

An attacker could replay one component's encrypted props (p) value as another component's slots (s) value, or vice versa.

LOW 2.9EPSS 0.14%

Does this matter?

Lower severity and a low EPSS score (0.14%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 2.9 LOWCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.14% probability · 4th percentile
CISA KEV: Not listed
Weakness: CWE-323, CWE-79
Affected: astro/astro
Source: security-advisories@github.com

References

https://github.com/withastro/astro/commit/3d82220a1549e699e34ed433f3846a919f4c02bdPatch
https://github.com/withastro/astro/pull/16457Issue Tracking, Patch
https://github.com/withastro/astro/security/advisories/GHSA-xr5h-phrj-8vxvVendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.