Is CVE-2026-48988 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-48988 being exploited in the wild.

How severe is CVE-2026-48988?

Medium severity, with a CVSS score of 5.3, published 17 June 2026.

Which products and versions are affected?

markdown-it (npm) <= 14.1.1, SEMVER:introduced=0,fixed=14.2.0.

Is there a fix for CVE-2026-48988?

Yes. markdown-it (npm): upgrade to 14.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-48988 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-48988?

Check whether you run markdown-it (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-48988: markdown-it denial of service in smartquotes rule

Q: Which products and versions are affected?

markdown-it (npm) <= 14.1.1, SEMVER:introduced=0,fixed=14.2.0.

Q: Is there a fix for CVE-2026-48988?

Yes. markdown-it (npm): upgrade to 14.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-48988 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-48988?

Check whether you run markdown-it (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-48988 · Severity: medium · CVSS 5.3 · Published 2026-06-17

markdown-it is a widely used library for converting Markdown text into HTML. A flaw in its typography feature allows an attacker to send a specially crafted document that causes the system to consume excessive CPU power. This can lead to a denial-of-service (DoS) condition, making the application slow or completely unresponsive for legitimate users.

Technologies: markdown-it (npm). Vendors: npm.

Quick answers

Is CVE-2026-48988 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-48988 being exploited in the wild.
How severe is CVE-2026-48988?: Medium severity, with a CVSS score of 5.3, published 17 June 2026.
Which products and versions are affected?: markdown-it (npm) <= 14.1.1, SEMVER:introduced=0,fixed=14.2.0.
Is there a fix for CVE-2026-48988?: Yes. markdown-it (npm): upgrade to 14.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-48988 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-48988?: Check whether you run markdown-it (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

markdown-it (npm): upgrade to 14.2.0 or later
```
npm install markdown-it@14.2.0
```

Technical details

A denial-of-service vulnerability exists in markdown-it versions 14.1.1 and below due to uncontrolled resource consumption in the smartquotes rule. When the 'typographer' option is enabled, the parser uses a replaceAt() helper function that performs string slicing and concatenation (an O(n) operation) for every quote character found. In inputs with a high density of quotation marks, this results in quadratic (O(n^2)) time complexity. A remote, unauthenticated attacker can exploit this by submitting a markdown payload with many consecutive quotes, leading to CPU exhaustion and service degradation. The issue is fixed in version 14.2.0 by optimizing how string replacements are handled.

Affected products

markdown-it markdown-it <= 14.1.1

Identifiers

CVE-2026-48988
GHSA-6v5v-wf23-fmfq

Timeline

2026-05-23: advisory: GitHub Security Advisory published
2026-06-17: disclosed: CVE-2026-48988 published to NVD
2026-06-17: patched: Fixed in version 14.2.0

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.