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Fencer Intel
high 7.5

CVE-2026-111758 json

markdown-it: Quadratic-time rendering of a single multi-line link reference definition with default options (regression since 14.0)

published 20d ago modified 12d ago also EUVD-2026-105358 , GHSA-gfr2-rv44-r23c

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 46%
public exploits
0
none known

Summary

markdown-it is a Markdown parser. From versions 14.1.0 to before 14.3.3, and 15.0.0 to before 15.0.3, a link reference definition whose label or title is never closed is O(n²) with default options. Continuation lines are pulled lazily with str += lineContent in src/rules_block/reference.ts, and the subsequent charCodeAt and slice calls flatten the V8 cons-string, copying everything collected so far; this runs before the rule decides the definition is invalid. No options are required to trigger it. This issue has been patched in versions 14.3.3 and 15.0.3.

Patch / fix

  • npm markdown-it 14.3.3, 15.0.3
  • markdown-it_project markdown-it 14.3.3, 15.0.3

Is CVE-2026-111758 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-111758 updated cvss 7.5

markdown-it: markdown-it: Denial of Service via unclosed link reference definitions

  • Red Hat Build of Podman Desktop rh-podman-desktop 3c6fc75a2a6cf5bb9b8a667fddcbbf428132badc
    affected: workaround, no fix available
  • Red Hat Ceph Storage 9 thrift
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-feature-server-rhel9, rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9 Red Hat OpenShift Dev Spaces devspaces/code-rhel9, devspaces/openvsx-rhel9 Red Hat Self-service automation portal 2 ansible-automation-platform/automation-portal, ansible-automation-platform/bootc-automation-portal-rhel9
    affected: workaround, no fix available
  • Red Hat Developer Hub 1 rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend
    not affected: vulnerable code not in execute path
  • Red Hat Hardened Images libgit2_1.9 1.9.7-3.1.hum1
    not affected: component not present
  • Red Hat OpenShift Dev Spaces devspaces/pluginregistry-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
12d ago

Exploit prediction

0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/markdown-it/markdown-it/security/advisories/GHSA-gfr2-rv44-r23c referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
npm markdown-it
>=14.1.0, <14.3.3
>=15.0.0, <15.0.3
14.3.3
15.0.3

Affected products

  • markdown-it markdown-it

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-407 Inefficient Algorithmic Complexity

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.