CVE-2026-105646: Ghost Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-fwh9-qg68-vxp4
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CVSS 4.9
CWE-1333
Published
Advisory Summary

CVE-2026-105646 is a MODERATE (CVSS 4.9) denial of service vulnerability (CWE-1333: Inefficient Regular Expression Complexity) affecting Ghost libraries in the npm ecosystem. The issue involves regular expression denial of service in content import. Remediation is available by upgrading affected packages to version 6.67.0.

CVE-2026-105646 at a Glance

CVE Identifier CVE-2026-105646
GHSA Identifier GHSA-fwh9-qg68-vxp4
Severity MODERATE
CVSS v3.1 Base Score 4.9
CWE Classification CWE-1333: Inefficient Regular Expression Complexity
Affected Product Ghost
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 4.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-105646

To remediate this vulnerability, upgrade all affected Ghost dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

ghost fixed: 6.67.0 
npm install ghost@6.67.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls ghost

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-105646, inspect your project dependencies using npm:

npm ls ghost

Analyze the terminal output to locate any version of Ghost in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.67.0), your application is affected.

Note: The npm ls ghost command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1333: Inefficient Regular Expression Complexity, where the product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential. In Ghost, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact A crafted content import file could cause excessive CPU usage, making the Ghost server unresponsive. Exploiting this requires Administrator access. ### Vulnerable versions This vulnerability is present in Ghost from v4.0.0 up to v6.65.0. ### Patches v6.67.0 contains a fix for this issue. ### How to update For self-hosters using Docker, find [Docker's official Ghost image here](https://hub.docker.com/_/ghost). Updating a Docker-based Ghost instance [is documented here](https://docs.ghost.org/install/docker#updating-ghost). If your Ghost is a Ghost-CLI install see our documentation on [updating it to the latest version here](https://docs.ghost.org/update). ### References Ghost thanks [ka3n1x](https://github.com/ka3n1x) for disclosing this vulnerability responsibly. ### For more information If you have any questions or comments about this advisory, email us at [security@ghost.org](mailto:security@ghost.org).

CVE-2026-105646 Affected Ghost Versions

1 component(s)
Fixed Versions:
6.67.0
Product / Package Ecosystem Affected Versions Fixed Version
ghost
npm/ghost
npm
≥ 4.0.0
< 6.67.0
6.67.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/TryGhost/Ghost/security/advisories/GHSA-fwh9-qg68-vxp4
NVD — CVE-2026-105646 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-105646
Ghost Source Repository REPOSITORY
https://github.com/TryGhost/Ghost/pull/31058
Security Fix Commit FIX COMMIT
https://github.com/TryGhost/Ghost/commit/88ae6d6d56f8a239cb38a8c89de02f034f50e2ce
Ghost Source Repository REPOSITORY
https://github.com/TryGhost/Ghost
Ghost Release RELEASE
https://github.com/TryGhost/Ghost/releases/tag/v6.66.0

Frequently Asked Questions

What is CVE-2026-105646?
CVE-2026-105646 is a security vulnerability in Ghost involving Regular Expression Denial of Service in Content Import under CWE-1333: Inefficient Regular Expression Complexity.
Which Ghost versions are affected?
Affected versions include releases prior to 6.67.0 across affected packages: ghost.
What version fixes CVE-2026-105646?
Upgrading to 6.67.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ghost affected?
Yes, ghost is affected in releases prior to 6.67.0. Upgrade your dependency to 6.67.0 or later.
What is the CVSS score of CVE-2026-105646?
CVE-2026-105646 has a CVSS v3.1 base score of 4.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-105646?
CVE-2026-105646 is classified under CWE-1333: Inefficient Regular Expression Complexity (The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.).
How can I check npm dependencies for CVE-2026-105646?
Run the dependency tree command: 'npm ls ghost'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-fwh9-qg68-vxp4",
  "modified" : "2026-10-07T20:42:53Z",
  "published" : "2026-10-07T20:42:53Z",
  "aliases" : [ "CVE-2026-105646" ],
  "summary" : "Ghost: Regular Expression Denial of Service in Content Import",
  "details" : "### Impact\n\nA crafted content import file could cause excessive CPU usage, making the Ghost server unresponsive. Exploiting this requires Administrator access.\n\n### Vulnerable versions\n\nThis vulnerability is present in Ghost from v4.0.0 up to v6.65.0.\n\n### Patches\n\nv6.67.0 contains a fix for this issue.\n\n### How to update\n\nFor self-hosters using Docker, find [Docker's official Ghost image here](https://hub.docker.com/_/ghost). Updating a Docker-based Ghost instance [is documented here](https://docs.ghost.org/install/docker#updating-ghost). \n\nIf your Ghost is a Ghost-CLI install see our documentation on [updating it to the latest version here](https://docs.ghost.org/update). \n\n### References\n\nGhost thanks [ka3n1x](https://github.com/ka3n1x) for disclosing this vulnerability responsibly.\n\n### For more information\n\nIf you have any questions or comments about this advisory, email us at [security@ghost.org](mailto:security@ghost.org).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "ghost"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "6.67.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/TryGhost/Ghost/security/advisories/GHSA-fwh9-qg68-vxp4"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-105646"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TryGhost/Ghost/pull/31058"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TryGhost/Ghost/commit/88ae6d6d56f8a239cb38a8c89de02f034f50e2ce"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/TryGhost/Ghost"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TryGhost/Ghost/releases/tag/v6.66.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1333" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-07T20:42:53Z",
    "nvd_published_at" : "2026-10-05T19:17:19Z"
  }
}