CVE-2026-48988 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-48988MEDIUM

markdown-it: Quadratic complexity DoS in smartquotes rule via replaceAt string operations

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  L    5.3   .0038   31.2     —

AFFECTED
  Product      Versions    Fixed
  markdown-it  < 14.2.0 –  —

TIMELINE
  May 26  Reserved by GitHub_M
  Jun 17  EXPLOIT PUBLISHED — CVE-2026-48988 (markdown-it). Public exploit reference added.
  Jun 17  Published (CNA: GitHub_M)

CWE-400 · CNA: GitHub_M · CVSS v3.1 · 2 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
May 26, 2026	Reserved	Reserved by GitHub_M
June 17, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-48988 (markdown-it). Public exploit reference added.
June 17, 2026	Published	Published (CNA: GitHub_M)

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
markdown-it	markdown-it	—	< 14.2.0	—

Weaknesses

CWE-400

References (2)

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]

Authoritative record: CVE-2026-48988 at cve.org

Vendors: markdown-it

Weaknesses: CWE-400

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-48988 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.