CVE-2026-45028

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

MEDIUM
6.1
CVSS Score
Published: May 13, 2026 at 03:50 PM UTC
Updated: October 26, 2026 at 05:10 PM UTC
2 products affected across 2 vendorsAstroAstro

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 6.1.10
v < 6.1.10
Affected range stops below 6.1.10, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/withastro/astro/security/advisories/GHSA-xr5h-phrj-8vxv
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/withastro/astro/pull/16457

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-323CWE-79

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