CVE-2026-126361
Astro: XSS via attribute injection in dynamic tag names
- Low 2.3
Description
Astro is a web framework for content-driven websites. Prior to 7.4.5, Astro rendered a string used as a dynamic element name as raw HTML after applying an incomplete character filter. A / in the string could make an HTML parser treat the remainder as attributes, allowing untrusted element-name input to inject event-handler markup. The .astro dynamic-tag renderer, JSX renderer, and MDX renderer were affected, and exploitation required an application to use request-controlled or stored untrusted data as all or part of an element name. This issue is fixed in version 7.4.5.
Key facts
- Published
- 12 Nov 2026
- Last changed
- 12 Nov 2026
- Assigned by
- GitHub_M
- EPSS
- 0.315% likely to be exploited in the next 30 days, higher than 24.773% of CVEs (scores for 15 Nov 2026)
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 2.3CVSS 4.0, Lowfrom the CNA (GitHub_M)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| withastro | astro |
|
Timeline
- 12 Nov 2026 Published
Weakness
Practice this bug class
HackZoneLabs has a hands-on lab on XSS (stored, reflected, DOM) (CWE-79).