Bug 2559062

Summary: CVE-2026-111766 markdownlint-cli2: markdown-it: Denial of Service via repeated unterminated inline HTML constructs [fedora-all]
Product: [Fedora] Fedora Reporter: Ronit Dey <rdey>
Component: markdownlint-cli2Assignee: Fabio Porcedda <fabio.porcedda>
Status: CLOSED ERRATA QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: rawhideCC: fabio.porcedda
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["5e93ff90-762f-4e5d-9cb6-91bcf096afbf"]}
Fixed In Version: markdownlint-cli2-0.24.0-1.fc45 markdownlint-cli2-0.24.0-1.fc44 markdownlint-cli2-0.24.0-1.fc43 Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-11-05 01:02:09 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2555815    

Description Ronit Dey 2026-10-22 14:59:38 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Fedora Update System 2026-10-27 17:53:41 UTC
FEDORA-2026-8f8cd892e5 (markdownlint-cli2-0.24.0-1.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-8f8cd892e5

Comment 2 Fedora Update System 2026-10-27 17:54:10 UTC
FEDORA-2026-6215800886 (markdownlint-cli2-0.24.0-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-6215800886

Comment 3 Fedora Update System 2026-10-27 18:08:33 UTC
FEDORA-2026-183d3c32a6 (markdownlint-cli2-0.24.0-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-183d3c32a6

Comment 4 Fedora Update System 2026-10-28 03:19:25 UTC
FEDORA-2026-183d3c32a6 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-183d3c32a6`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-183d3c32a6

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2026-10-28 03:46:30 UTC
FEDORA-2026-8f8cd892e5 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-8f8cd892e5`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-8f8cd892e5

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 6 Fedora Update System 2026-10-28 04:02:36 UTC
FEDORA-2026-6215800886 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-6215800886`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-6215800886

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 7 Fedora Update System 2026-11-05 01:02:09 UTC
FEDORA-2026-8f8cd892e5 (markdownlint-cli2-0.24.0-1.fc45) has been pushed to the Fedora 45 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 8 Fedora Update System 2026-11-05 01:26:26 UTC
FEDORA-2026-6215800886 (markdownlint-cli2-0.24.0-1.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 9 Fedora Update System 2026-11-05 01:46:00 UTC
FEDORA-2026-183d3c32a6 (markdownlint-cli2-0.24.0-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.