CVSS 4.0
2.3 lowCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:NCVE-2026-126362
Astro: Reflected XSS via unescaped slot names in @astrojs/svelte
Low (2.3) in withastro astro. Fixed in @astrojs/svelte 9.1.2.
On this page
Astro is a web framework for content-driven websites. From 5.7.3 until 9.1.2, the @astrojs/svelte renderer inserted a named slot into the quoted name attribute of an astro-slot wrapper without HTML escaping. Request-controlled slot names containing a quote could terminate the attribute and inject active HTML. Exploitation required a hydrated Svelte component using a client:* directive and dynamic rendering of the attacker-chosen slot; components that did not render that slot emitted only Astro's escaped fallback content. Both server rendering and client-side hydration used the unsafe slot name. This issue is fixed in version 9.1.2.
Severity
- CWE
- CWE-79 Improper Neutralization of Input During Web Page Generation (Cross-site Scripting)
- OWASP Top 10
- A05:2025 Injection
- Published
- Assigned by
- GitHub_M (CNA)
- NVD analysis
- Not in the NVD yet
- Record from
- the CVE List, synced
Ask an AI about this CVE
Show the prompt
Explain CVE-2026-126362 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-126362?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-126362?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-126362 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Badge for a README or a site
An image that stays current: it is drawn from the data each time it is fetched (a host that proxies images, as GitHub does, may show its copy for a while). Markdown:
[](https://cve.bz/cve/CVE-2026-126362)
HTML:
<a href="https://cve.bz/cve/CVE-2026-126362"><img src="https://cve.bz/cve/badge/CVE-2026-126362.svg" alt="CVE-2026-126362"></a>
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| withastro astro | >= 5.7.3, < 9.1.2 |
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-f4j9-crrj-867q | npm | @astrojs/svelte | >=5.7.3 <9.1.2 | 9.1.2 |
Attack patterns (CAPEC)
- CAPEC-63 Cross-Site Scripting (XSS) Likelihood: High · Severity: Very High
- CAPEC-85 AJAX Footprinting Likelihood: High · Severity: Low
- CAPEC-209 XSS Using MIME Type Mismatch Severity: Medium
- CAPEC-588 DOM-Based XSS Likelihood: High · Severity: Very High
- CAPEC-591 Reflected XSS Likelihood: High · Severity: Very High
- CAPEC-592 Stored XSS Likelihood: High · Severity: Very High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.