---
id: CVE-2026-114127
title: 'Astro: Arbitrary CSS injection in Astro View Transitions'
summary: >-
  Astro is a web framework for content-driven websites. From 7.1.0 until 7.3.3,
  Astro's server-side View Transition CSS generator does not keep string
  animation properties within their generated declarations. An application that
  passes att…
severity: low
cvss: 2.3
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'
cvssSource: cna
cwe:
  - CWE-79
vendor: withastro
product: astro
affected:
  - 'astro >= 7.1.0, < 7.3.3'
published: '2026-10-21'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T17:30:03.860Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-114127'
references:
  - url: 'https://github.com/withastro/astro/security/advisories/GHSA-mpr7-6m5w-76rw'
    label: 'https://github.com/withastro/astro/security/advisories/GHSA-mpr7-6m5w-76rw'
  - url: 'https://github.com/withastro/astro/pull/17970'
    label: 'https://github.com/withastro/astro/pull/17970'
  - url: >-
      https://github.com/withastro/astro/commit/0b4dc3a211910b589d3805ab4dfedf11b0e712bb
    label: >-
      https://github.com/withastro/astro/commit/0b4dc3a211910b589d3805ab4dfedf11b0e712bb
  - url: 'https://github.com/withastro/astro/releases/tag/astro@7.3.3'
    label: 'https://github.com/withastro/astro/releases/tag/astro@7.3.3'
tags:
  - cve.org
ingestedAt: '2026-10-21T18:09:27.277Z'
---

## Overview

Astro is a web framework for content-driven websites. From 7.1.0 until 7.3.3, Astro's server-side View Transition CSS generator does not keep string animation properties within their generated declarations. An application that passes attacker-controlled data into properties such as duration, delay, easing, direction, fillMode, or animation names can allow CSS delimiters to terminate the declaration and add attacker-selected rules to the server-rendered page. The generated stylesheet still escapes literal less-than characters, so the injected content cannot terminate the style element or directly inject HTML or JavaScript. The injected CSS can conceal or reposition content, add generated text, and otherwise misrepresent the interface; some applications may also expose data already present in selectable DOM attributes through conditional resource loads. This issue is fixed in 7.3.3.

## Affected

- `astro >= 7.1.0, < 7.3.3`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.