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TI-2026-78907 Aliases CVE-2026-114127GHSA-mpr7-6m5w-76rw

Arbitrary CSS injection in Astro View Transitions

Priority MEDIUM 45CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
Present
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-79.

Summary

A remote attacker without privileges can add CSS rules to server-rendered pages in Astro from 7.1.0 before 7.3.3 when an application passes attacker-controlled data into View Transition animation properties. This happens because CWE-79 lets CSS delimiters end a declaration, so the injected rules can hide or move content and misrepresent the interface. The injected CSS cannot directly inject HTML or JavaScript.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00498 42nd percentileScored 2026-11-07
Fix Partial astro (withastro): 7.3.3astro (npm): 7.3.3Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
withastroastro7.1.0 to before 7.3.37.3.3Patch availableCNA
—astro (npm)7.1.0 to before 7.3.37.3.3Patch availableGHSA-mpr7-6m5w-76rw
  • astro Vendorwithastro Affected 7.1.0 to before 7.3.3 Fixed in 7.3.3 Patch available CNA
  • astro (npm) Vendor— Affected 7.1.0 to before 7.3.3 Fixed in 7.3.3 Patch available GHSA-mpr7-6m5w-76rw

Remediation

Upgrade the astro npm package to 7.3.3, which fixes this issue. Red Hat lists Red Hat OpenShift AI (RHOAI) as affected with no fix available.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

  • Fix · CNA astro (withastro) Fixed in 7.3.3
  • Fix · GHSA-mpr7-6m5w-76rw astro (npm) Fixed in 7.3.3 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-21 Threatist record created from CVE-2026-114127
  2. 2026-10-22 Affected versions changed · Red Hat
  3. 2026-10-22 CVSS score added · Red Hat
  4. 2026-10-22 Alias added: GHSA-mpr7-6m5w-76rw
  5. 2026-10-22 Fix available: npm/[email protected] · GHSA-mpr7-6m5w-76rw
  6. 2026-10-22 CVSS score added · GHSA-mpr7-6m5w-76rw
  7. 2026-10-22 Weakness changed · GHSA-mpr7-6m5w-76rw
  8. 2026-10-22 6 new references · GHSA-mpr7-6m5w-76rw
  9. 2026-10-30 CISA SSVC decision points changed
  10. 2026-10-30 Priority changed: LOW → MEDIUM

References

Advisory 1

Other 5

  • TI-2026-26147 Astro: Unauthenticated Path Override via `x-astro-path` / `x_astro_path` CVSS 3.1CRITICAL 9.1
  • TI-2026-42600 Astro 6.4.7 Authorization Bypass via Decode Iteration Limit and Rewrite Path Canonicalization Mismatch CVSS 3.1HIGH 8.2
  • TI-2024-37142 Server source code is exposed to the public if sourcemaps are enabled CVSS 4.0HIGH 7.8
  • TI-2025-35987 Astro Cloudflare adapter is vulnerable to Server-Side Request Forgery via /_image endpoint CVSS 3.1HIGH 7.2
  • TI-2025-34958 Unauthorized third-party images in Astro’s _image endpoint CVSS 4.0MEDIUM 6.9
  • TI-2026-51542 Astro: Unauthenticated path override in the @astrojs/vercel ISR function CVSS 3.1MEDIUM 6.5
See all 43 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences