CVE catalog
CVE-2026-111766
markdown-it is a Markdown parser. Prior to 14.3.3 and 15.0.3, when the html option or commonmark preset is enabled and the constructs occur inside a paragraph, attacker-controlled Markdown containing
- Severity
- Low · CVSS 3.7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 0.43% · Oct 25, 2026
markdown-it is a Markdown parser. Prior to 14.3.3 and 15.0.3, when the html option or commonmark preset is enabled and the constructs occur inside a paragraph, attacker-controlled Markdown containing repeated unterminated inline HTML comments, processing instructions, declarations, or CDATA sections reaches src/rules_inline/html_inline.ts. Its HTML_TAG_RE match searches the remaining suffix for the appropriate terminator; when no terminator is present, parsing advances to the next opener and repeats the match over overlapping input, causing quadratic processing and denial of service through event-loop blocking or an unresponsive browser main thread. HTML blocks and the default HTML-disabled configuration are not affected by these payloads. This issue is fixed in versions 14.3.3 and 15.0.3.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | node-markdown-it | sid | 22.2.3+dfsg+~12.2.3-5 | vulnerable |
| Debian | node-markdown-it | forky | 22.2.3+dfsg+~12.2.3-5 | vulnerable |
| Debian | node-markdown-it | trixie | 22.2.3+dfsg+~12.2.3-2 | vulnerable |
| Debian | node-markdown-it | bookworm | 22.2.3+dfsg+~12.2.3-2 | vulnerable |
| Ubuntu | node-markdown-it | 22.04 | 10.0.0+dfsg-2 | vulnerable |
| Ubuntu | node-markdown-it | 22.04 | 10.0.0+dfsg-3 | vulnerable |
| Ubuntu | node-markdown-it | 22.04 | 10.0.0+dfsg-3.1 | vulnerable |
| Ubuntu | node-markdown-it | 22.04 | 10.0.0+dfsg-4 | vulnerable |
| Ubuntu | node-markdown-it | 22.04 | 10.0.0+dfsg-5 | vulnerable |
| Ubuntu | node-markdown-it | 22.04 | 10.0.0+dfsg-6 | vulnerable |
| Ubuntu | node-markdown-it | 24.04 | 22.2.3+dfsg+~12.2.3-2 | vulnerable |
| Ubuntu | node-markdown-it | 26.10 | 22.2.3+dfsg+~12.2.3-4 | vulnerable |
| Ubuntu | node-markdown-it | 26.10 | 22.2.3+dfsg+~12.2.3-5 | vulnerable |
| Ubuntu | node-markdown-it | 26.04 | 22.2.3+dfsg+~12.2.3-2 | vulnerable |
| Ubuntu | node-markdown-it | 26.04 | 22.2.3+dfsg+~12.2.3-4 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | node-markdown-it | source | sid | (unfixed) | not yet assigned | Not reported | [1151932] |
| Debian | node-markdown-it | source | forky | (unfixed) | not yet assigned | Not reported | [1151932] |
| Debian | node-markdown-it | source | trixie | (unfixed) | not yet assigned | Not reported | [1151932] |
| Debian | node-markdown-it | source | bookworm | (unfixed) | not yet assigned | Not reported | [1151932] |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [node-markdown-it]Affected
Details (2)
22.2.3+dfsg+~12.2.3-2· all · bookwormAffected
nvd · node-markdown-it · debian · bookworm; nvd · node-markdown-it · debian · 12
22.2.3+dfsg+~12.2.3-2· all · bookwormAffected
nvd · node-markdown-it · debian · bookworm; nvd · node-markdown-it · debian · 12
[Debian 13 (Trixie)]
- [node-markdown-it]Affected
Details (2)
22.2.3+dfsg+~12.2.3-2· all · trixieAffected
nvd · node-markdown-it · debian · 13
22.2.3+dfsg+~12.2.3-2· all · trixieAffected
nvd · node-markdown-it · debian · 13
Observed:
References
- [https://github.com/markdown-it/markdown-it/commit/928bc8c11ded60181c0e7fc5aa954eec582e8e79]
- [https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503]
- [https://github.com/markdown-it/markdown-it/releases/tag/14.3.3]
- [https://github.com/markdown-it/markdown-it/releases/tag/15.0.3]
- [https://github.com/markdown-it/markdown-it/security/advisories/GHSA-vfgh-jcmw-g37q]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-111766]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-111766]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-111766]
- [https://security-tracker.debian.org/tracker/CVE-2026-111766]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-111766.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]