CVE-2026-59727
What it is
Astro is a web framework for content-driven websites. In versions 3.10.0 through 7.0.3, when a transition:persist, transition:scope, or transition:persist-props directive is applied to a client-hydrated (client:*) component, Astro copied the directive value onto the rendered <astro-island> element without HTML-escaping it. If a developer reflects attacker-controlled input into one of these directives, an attacker can break out of the attribute and inject arbitrary HTML/JavaScript into the server-rendered output, resulting in reflected cross-site scripting (XSS). Exploitation requires the application developer to have written a non-idiomatic pattern — passing untrusted, request-derived input directly into a transition directive. Astro applications that do not route untrusted input into these directives are unaffected. This issue has been fixed in version 7.0.4.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.4% in the next 30 days (EPSS).
- Severity: 2.1 LOW (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-79 · Cross-site scripting
- Record status
- Deferred
Attack profile CVSS 4.0 · 2.1
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- Present
- Privileges needed
- None
- User interaction
- Active
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-59727.md and follow it. Check whether this project is affected by CVE-2026-59727. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/withastro/astro/commit/7ba0bb1dc7516e88caff9abd7767322af44b0294
- https://github.com/withastro/astro/pull/17212
- https://github.com/withastro/astro/releases/tag/[email protected]
- https://github.com/withastro/astro/security/advisories/GHSA-7pw4-f3q4-r2p2
- https://github.com/withastro/astro/security/advisories/GHSA-7pw4-f3q4-r2p2
References
- https://github.com/withastro/astro/commit/7ba0bb1dc7516e88caff9abd7767322af44b0294
- https://github.com/withastro/astro/pull/17212
- https://github.com/withastro/astro/releases/tag/[email protected]
- https://github.com/withastro/astro/security/advisories/GHSA-7pw4-f3q4-r2p2
- https://github.com/withastro/astro/security/advisories/GHSA-7pw4-f3q4-r2p2