CVE-2026-73422: withastro astro · Cross-site Scripting
Affects withastro astroSource CVE Database V5
Not known to be exploited · CVSS 5.3 Medium : upgrade to 7.1.0 when convenient.
Data as of 9 Nov 2026, 23:24 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.1.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 12 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade withastro astro to 7.1.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| withastroastro | Affected
| Fixed in
|
npmastropkg:npm/astroOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
This vulnerability is fixed in Astro version 7.1.0. Users should upgrade to version 7.1.0 or later to remediate the issue. Until upgrading, avoid passing untrusted input into View Transition animation properties in server-rendered or on-demand routes to reduce risk.
Description
Astro is a web framework for content-driven websites. From 2.9.0 until 7.1.0, Astro's server-side View Transition CSS generator interpolates animation properties into an inline style element without escaping them for CSS and HTML contexts. An attacker-controlled View Transition animation value such as duration can terminate the generated style element and inject arbitrary HTML or JavaScript. The affected code is packages/astro/src/runtime/server/transition.ts; renderTransition passes sheet.toString() into markHTMLString(), while addAnimationProperty serializes duration through toTimeValue() and also handles easing, direction, delay, fillMode, and name. Exploitation requires an on-demand or server-rendered route to pass attacker-controlled data into a View Transition animation definition and can execute arbitrary JavaScript in the affected application's origin, allowing access to sensitive page data and authenticated actions available to the victim. This issue is fixed in version 7.1.0.
References
- github.com/withastro/astro/security/advisories/GHSA-4g3v-8h47-v7g6 (opens in a new tab)
- github.com/withastro/astro/pull/17393 (opens in a new tab)
- github.com/withastro/astro/commit/092da560eea77ee63a3e2c583c80d8238544e42b (opens in a new tab)
- github.com/withastro/astro/releases/tag/astro@7.1.0 (opens in a new tab)