CVE-2026-114127

Astro: Arbitrary CSS injection in Astro View Transitions

Published Oct 21, 2026 CVSS 4.0 · 2.3 Low EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-mpr7-6m5w-76rw Astro: Arbitrary CSS injection in Astro View Transitions
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Weaknesses CWE-140
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N'}

threat_severity

Moderate

Type Values Removed Values Added
First Time appeared Astro
Astro astro
Withastro
Withastro astro
Vendors & Products Astro
Astro astro
Withastro
Withastro astro
Type Values Removed Values Added
Description 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.
Title Astro: Arbitrary CSS injection in Astro View Transitions
Weaknesses CWE-79
References
Metrics cvssV4_0

{'score': 2.3, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 30, 2026, 8:16 PM
Reserved
Oct 20, 2026, 9:53 PM
Status
Awaiting Analysis
Published
Oct 21, 2026, 6:17 PM
Modified
Oct 30, 2026, 9:16 PM
Severity
Moderate
Public date
Oct 21, 2026, 5:30 PM