CVE-2026-48988
markdown-it: Quadratic complexity DoS in smartquotes rule via replaceAt string operations
Description
markdown-it is a Markdown parser. Versions 14.1.1 and below contain a denial-of-service vulnerability when typographer: true is enabled, due to quadratic (O(n^2)) processing in the smartquotes rule. The issue stems from repeatedly modifying strings with replaceAt(), which performs O(n) slicing and concatenation per quote character. This can cause excessive CPU consumption when parsing quote-heavy, user-supplied markdown and may let attackers degrade or disrupt service availability. Although typographer is disabled by default, many production apps enable it for smart typography, making the issue relevant. This issue has been fixed in version 14.2.0.
INFO
Published Date :
June 17, 2026, 9:16 p.m.
Last Modified :
June 24, 2026, 7:06 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update markdown-it to version 14.2.0.
- Disable the typographer option if updating is not possible.
Public PoC/Exploit Available at Github
CVE-2026-48988 has a 4 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-48988.
| URL | Resource |
|---|---|
| https://github.com/markdown-it/markdown-it/commit/9ce2087562c45d1e5ddd9f76b990f4b3fbe040e5 | Patch |
| https://github.com/markdown-it/markdown-it/security/advisories/GHSA-6v5v-wf23-fmfq | Exploit Mitigation Vendor Advisory |
| https://github.com/markdown-it/markdown-it/security/advisories/GHSA-6v5v-wf23-fmfq | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-48988 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-48988
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
A self-hosted F-Droid repo with a modern app-store UI, public + private apps, invite-only signups and SSO. Hardened, rootless images on GHCR.
android-store fdroid fdroid-repo store docker f-droid f-droidrepos fastapi material-design nextjs self-hosted
Makefile Dockerfile Python Mako TypeScript CSS JavaScript Shell
None
Dockerfile
NV Digital Open Operator System (NVoOS) is an Object-Oriented AI framework for WordPress connecting your data with OpenAI, Gemini, Anthropic, DeepSeek, Hugging Face, Cloudflare, OpenRouter & Ollama (Local) models. Create & manage AI Assistants that can interact with users, access WordPress (API) data, & perform as a MCP Server & Chat Agent
ai ai-agents ai-tools antropic-claude cloudflare-workers-ai google-gemini huggingface lm-studio mcp ollama-api ollama-client openai-api wordpress-plugin
PHP CSS JavaScript Shell HTML Python Dockerfile TypeScript Batchfile SCSS
None
JavaScript TypeScript PowerShell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-48988 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-48988 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 24, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:markdown-it_project:markdown-it:*:*:*:*:*:*:*:* versions up to (excluding) 14.2.0 Added Reference Type GitHub, Inc.: https://github.com/markdown-it/markdown-it/commit/9ce2087562c45d1e5ddd9f76b990f4b3fbe040e5 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/markdown-it/markdown-it/security/advisories/GHSA-6v5v-wf23-fmfq Types: Exploit, Mitigation, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/markdown-it/markdown-it/security/advisories/GHSA-6v5v-wf23-fmfq Types: Exploit, Mitigation, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 18, 2026
Action Type Old Value New Value Added Reference https://github.com/markdown-it/markdown-it/security/advisories/GHSA-6v5v-wf23-fmfq Added SSVC {'id': 'CVE-2026-48988', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-18T19:41:23.675536Z'} -
New CVE Received by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'markdown-it', 'product': 'markdown-it', 'versions': [{'status': 'affected', 'version': '< 14.2.0'}]}] Added Description markdown-it is a Markdown parser. Versions 14.1.1 and below contain a denial-of-service vulnerability when typographer: true is enabled, due to quadratic (O(n^2)) processing in the smartquotes rule. The issue stems from repeatedly modifying strings with replaceAt(), which performs O(n) slicing and concatenation per quote character. This can cause excessive CPU consumption when parsing quote-heavy, user-supplied markdown and may let attackers degrade or disrupt service availability. Although typographer is disabled by default, many production apps enable it for smart typography, making the issue relevant. This issue has been fixed in version 14.2.0. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-400 Added Reference https://github.com/markdown-it/markdown-it/commit/9ce2087562c45d1e5ddd9f76b990f4b3fbe040e5 Added Reference https://github.com/markdown-it/markdown-it/security/advisories/GHSA-6v5v-wf23-fmfq