GHSA-cgc2-rcrh-qr5x BIT-ghost-2026-29053 CVE-2026-29053
Ghost Vulnerable to Remote Code Execution via Malicious Themes
- Severity
- 7.6 / 10
- Critical · CVSS 3.1
- Exploit chance (EPSS)
- 4.90%
- Chance of exploitation in the next 30 days. Higher than 92.10% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
- Fix
6.19.1- Upgrade ghost to this version or later
Description
Impact
Specifically crafted malicious themes can execute arbitrary code on the server running Ghost.
Vulnerable Versions
This vulnerability is present in Ghost v0.7.2 to v6.19.0.
Patches
v6.19.1 contains a fix for this issue.
Workarounds
Ghost generally recommends users refrain from installing untrusted themes. If a malicious theme has already been installed, it is recommended to uninstall the theme and then inspect it to understand its impact, which will be attack-specific.
References
Ghost thanks Cristian-Alexandru Staicu at Endor Labs for disclosing this vulnerability responsibly.
For more information
If there are any questions or comments about this advisory, email Ghost at security@ghost.org.
Affected versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| ghost | >= 0.7.2, < 6.19.1 |
6.19.1 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
ghost npm → 6.19.1
- npm
npm install ghost@6.19.1- yarn
yarn add ghost@6.19.1- pnpm
pnpm add ghost@6.19.1
Severity breakdown
CVSS 3.1 7.6
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- High
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Weakness
CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How to prevent it
- Requirements: Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Implementation: Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-x3mg-q38v-m562 Ghost: Authorization Issue Allowed Author Role to Delete any Post | Medium | Also affects ghost |
| GHSA-8575-cr6v-7jh4 Ghost: Stored XSS via SVG Uploads Bypassing Sanitization | High | Also affects ghost |
| GHSA-r7f2-6fj8-6fg2 Ghost: Private IP Filtering Bypass via IPv6 Transition Addresses | Medium | Also affects ghost |
| GHSA-322m-ff4g-9vx9 Ghost: Server-Side Request Forgery in Bookmark Fetching | Medium | Also affects ghost |
| GHSA-fwh9-qg68-vxp4 Ghost: Regular Expression Denial of Service in Content Import | Medium | Also affects ghost |
| GHSA-9m4w-fmjw-fvjq Ghost: Regular Expression Denial of Service in External Media Inliner | Medium | Also affects ghost |
| GHSA-hqq2-xqr2-fmx2 Ghost : Stored XSS via SVG Files in Content Imports | Medium | Also affects ghost |
| GHSA-69qc-f5m6-889c Ghost: Stored XSS via Embed Card Previews | High | Also affects ghost |
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