Back to overview

CVE-2026-59729

MEDIUM Exploitation: PoC
5.1
CVSS 4.0
Description
Astro is a web framework for content-driven websites. Versions prior to 7.0.6 are vulnerable to XSS through unescaped spread attribute names in renderHTMLElement. The fix for CVE-2026-54298 (GHSA-jrpj-wcv7-9fh9) added an INVALID_ATTR_NAME_CHAR guard to addAttribute() so that spread-prop attribute names containing "' >/= or whitespace are dropped. A second attribute-rendering path, renderHTMLElement() in packages/astro/src/runtime/server/render/dom.ts, has its own inline attribute loop that does not go through addAttribute() and was not updated. It interpolates the attribute name unescaped and only escapes the value, so untrusted prop keys spread onto a native-HTMLElement-subclass component can still break out of the attribute context. This issue has been fixed in version 7.0.6.

Metadata

CVE ID
CVE-2026-59729
State
PUBLISHED
Assigner
GitHub_M
Reserved
2026-07-06 15:34 UTC
Published
2026-07-27 19:38 UTC
Last updated
2026-07-28 13:48 UTC
Primary CWE
CWE-79
CWE-79: Improper Neutralization of Input During Web Page Gen…
Vendor / Product
withastro / astro
Sources
cve.org  ·  NVD

Severity & Metrics

5.1 MEDIUM CVSS 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
SSVC — CISA Coordinator
Exploitation
PoC
Automatable
no
Tech. Impact
partial
Affected products (1)
VendorProductPlatformVersions
withastro astro — < 7.0.6
Weakness (CWE)
CWESourceDescription
CWE-79 cna CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSS scores (1)
ScoreSeverityVersionSourceVector
5.1 MEDIUM 4.0 cna CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
References (4)
Back to overview