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Full vulnerability report · 2026
CVE-2026-2327High confidence

Versions of the package markdown-it from 13.0.0 and before 14.1.1 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the use of the regex /\*+$/ in the linkify function

Unknown · markdown-it

6.9MediumCVSS 4.0
Recommended action
Within 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:High, raised one band.upgradedsince 12 Feb 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.69% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Unknown markdown-it and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

5 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcenode-markdown-itNot affectedDebian marks this release not affected (fixed-version marker 0).Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcenode-markdown-itNot affectedDebian marks this release not affected (fixed-version marker 0).Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcenode-markdown-itNot affectedDebian marks this release not affected (fixed-version marker 0).Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcenode-markdown-itNot affectedDebian marks this release not affected (fixed-version marker 0).Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivenode-markdown-itUnder evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Open-source package ranges2 source-attributed ranges

These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
npmmarkdown-it>= 13.0.0, < 14.1.114.1.1GitHub advisory ↗github reviewed aggregator · 13 Feb 2026
npmmarkdown-itSEMVER: introduced 13.0.0; fixed 14.1.114.1.1OSV record ↗aggregator derived · 10 Sep 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-2327 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitymarkdown-it: markdown-it: Denial of Service via Regular Expression Denial of Service in linkify function
4 fixed

The vendor explicitly identifies these products or versions as containing the fix.

  • registry.redhat.io/devspaces/openvsx-rhel9@sha256:341c8f0f91bd41d4bded00443cd7ab2ddab4972a5ee1ddff4dcbfcdd5c2764f4_arm64 as a component of Red Hat OpenShift Dev Spaces 3.28
  • registry.redhat.io/devspaces/openvsx-rhel9@sha256:94d4124c7884916fbce4af4655b8a5eef5b62df6a21afabf6461bbb898d895b9_ppc64le as a component of Red Hat OpenShift Dev Spaces 3.28
  • registry.redhat.io/devspaces/openvsx-rhel9@sha256:e9eef99fc45b2ce06fadacf3db85e6e2f1fbabb16afc250929387ce2589732c3_amd64 as a component of Red Hat OpenShift Dev Spaces 3.28
  • registry.redhat.io/devspaces/openvsx-rhel9@sha256:fe8c450b4f48bd6935495464a3c2a7bfcf29e2bee04d44f9e60344351c49b049_s390x as a component of Red Hat OpenShift Dev Spaces 3.28
Summary
A flaw was found in markdown-it. A remote attacker can exploit this Regular Expression Denial of Service (ReDoS) vulnerability by providing a specially crafted input containing a long sequence of asterisk characters followed by a non-matching character to the `linkify` function. This triggers excessive backtracking in the regular expression, leading to a denial-of-service condition.
Remediation
Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-7037

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Versions of the package markdown-it from 13.0.0 and before 14.1.1 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the use of the regex /\*+$/ in the linkify function. An attacker can supply a long sequence of * characters followed by a non-matching character, which triggers excessive backtracking and may lead to a denial-of-service condition.

What

Versions of the package markdown-it from 13.0.0 and before 14.1.1 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the use of the regex /\*+$/ in the linkify function. An attacker can supply a long sequence of * characters followed by a non-matching character, which triggers excessive backtracking and may lead to a denial-of-service condition.

Why

The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

Versions of the package markdown-it from 13.0.0 and before 14.1.1 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the use of the regex /\*+$/ in the linkify function. An attacker can supply a long sequence of * characters followed by a non-matching character, which triggers excessive backtracking and may lead to a denial-of-service condition.

Why

The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.

Likely attack path
a network path → Inefficient Regular Expression Complexity → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-1333 ↗

CWE-1333: Inefficient Regular Expression Complexity. The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VALowVulnerable-system availability: A successful attack can cause a limited loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedDenial of serviceCWE-1333Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-3046IBM Concert: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM Concert ausnutzen, um beliebigen Programmcode auszuführen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren, um einen Cross-Site Scripting Angriff durchzuführen, um einen SQL-Injection Angriff durchzuführen und um Sicherheitsvorkehrungen zu umgehen.

Official advisory ↗
BSI · German · WID-SEC-2026-0574IBM App Connect Enterprise: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM App Connect Enterprise ausnutzen, um einen Denial of Service Angriff durchzuführen, um Sicherheitsvorkehrungen zu umgehen, um Informationen offenzulegen, und um einen Cross-Site Scripting Angriff durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260218Security Bulletin 18 Feb 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 18 Feb 2026, published on 18 February 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1256Multiples vulnérabilités dans les produits IBM

d?id=CVE-2026-16440 Référence CVE CVE-2026-16524 https://www.cve.org/CVERecord?id=CVE-2026-16524 Référence CVE CVE-2026-16526 https://www.cve.org/CVERecord?id=CVE-2026-16526 Référence CVE CVE-2026-16527 https://www.cve.org/CVERecord?id=CVE-2026-16527 Référence CVE CVE-2026-16529 https://www.cve.org/CVERecord?id=CVE-2026-16529 Référence CVE CVE-2026-17523 https://www.cve.org/CVERecord?id=CVE-2026-17523 Référence CVE CVE-2026-18401 https://www.cve.org/CVERecord?id=CVE-2026-18401 Référence CVE CVE-2026-18446 https://www.cve.org/CVERecord?id=CVE-2026-18446 Référence CVE CVE-2026-18525 https://www.cve.org/CVERecord?id=CVE-2026-18525 Référence CVE CVE-2026-2327 https://www.cve.org/CVERecord?id=CVE-2026-2327 Référence CVE CVE-2026-2359 https://www.cve.org/CVERecord?id=CVE-2026-2359 Référence CVE CVE-2026-23745 https://www.cve.org/CVERecord?id=CVE-2026-23745 Référence CVE CVE-2026-23901 https://www.cve.org/CVERecord?id=CVE-2026-23901 Référence CVE CVE-2026-23903 https://www.cve.org/CVERecord?id=CVE-2026-23903 Référence CVE CVE-2026-2391 https://www.cve.org/CVERecord?id=CVE-2026-2391 Référence CVE CVE-2026-23950 https://www.cve.org/CVERecord?id=CVE-2026-23950 Référence CVE CVE-2026-24842 https://www.cve.org/CVERecord?id=CVE-2026-24842 Référence CVE CVE-2026-25639 https://www.cve.org/CVERecord?id=CVE-2

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0834Multiples vulnérabilités dans les produits IBM

ERecord?id=CVE-2026-11707 Référence CVE CVE-2026-11708 https://www.cve.org/CVERecord?id=CVE-2026-11708 Référence CVE CVE-2026-11712 https://www.cve.org/CVERecord?id=CVE-2026-11712 Référence CVE CVE-2026-11714 https://www.cve.org/CVERecord?id=CVE-2026-11714 Référence CVE CVE-2026-1352 https://www.cve.org/CVERecord?id=CVE-2026-1352 Référence CVE CVE-2026-13772 https://www.cve.org/CVERecord?id=CVE-2026-13772 Référence CVE CVE-2026-1577 https://www.cve.org/CVERecord?id=CVE-2026-1577 Référence CVE CVE-2026-1718 https://www.cve.org/CVERecord?id=CVE-2026-1718 Référence CVE CVE-2026-22029 https://www.cve.org/CVERecord?id=CVE-2026-22029 Référence CVE CVE-2026-2327 https://www.cve.org/CVERecord?id=CVE-2026-2327 Référence CVE CVE-2026-2391 https://www.cve.org/CVERecord?id=CVE-2026-2391 Référence CVE CVE-2026-24001 https://www.cve.org/CVERecord?id=CVE-2026-24001 Référence CVE CVE-2026-24040 https://www.cve.org/CVERecord?id=CVE-2026-24040 Référence CVE CVE-2026-24043 https://www.cve.org/CVERecord?id=CVE-2026-24043 Référence CVE CVE-2026-24133 https://www.cve.org/CVERecord?id=CVE-2026-24133 Référence CVE CVE-2026-24737 https://www.cve.org/CVERecord?id=CVE-2026-24737 Référence CVE CVE-2026-25535 https://www.cve.org/CVERecord?id=CVE-2026-25535 Référence CVE CVE-2026-25639 https://www.cve.org/CVERecord?id=CVE

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0424Multiples vulnérabilités dans les produits IBM

d?id=CVE-2025-40909 Référence CVE CVE-2025-68161 https://www.cve.org/CVERecord?id=CVE-2025-68161 Référence CVE CVE-2026-21884 https://www.cve.org/CVERecord?id=CVE-2026-21884 Référence CVE CVE-2026-21925 https://www.cve.org/CVERecord?id=CVE-2026-21925 Référence CVE CVE-2026-21932 https://www.cve.org/CVERecord?id=CVE-2026-21932 Référence CVE CVE-2026-21933 https://www.cve.org/CVERecord?id=CVE-2026-21933 Référence CVE CVE-2026-21945 https://www.cve.org/CVERecord?id=CVE-2026-21945 Référence CVE CVE-2026-22029 https://www.cve.org/CVERecord?id=CVE-2026-22029 Référence CVE CVE-2026-22030 https://www.cve.org/CVERecord?id=CVE-2026-22030 Référence CVE CVE-2026-2327 https://www.cve.org/CVERecord?id=CVE-2026-2327 Référence CVE CVE-2026-23950 https://www.cve.org/CVERecord?id=CVE-2026-23950 Référence CVE CVE-2026-24688 https://www.cve.org/CVERecord?id=CVE-2026-24688 Référence CVE CVE-2026-24842 https://www.cve.org/CVERecord?id=CVE-2026-24842 Référence CVE CVE-2026-25528 https://www.cve.org/CVERecord?id=CVE-2026-25528 Référence CVE CVE-2026-25639 https://www.cve.org/CVERecord?id=CVE-2026-25639 Référence CVE CVE-2026-26007 https://www.cve.org/CVERecord?id=CVE-2026-26007 Référence CVE CVE-2026-26013 https://www.cve.org/CVERecord?id=CVE-2026-26013 Référence CVE CVE-2026-27024 https://www.cve.org/CVERecord?id=C

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-004739markdown-it projectのmarkdown-itにおける非効率的な正規表現の複雑さに関する脆弱性

パッケージmarkdown-itのバージョン13.0.0から14.1.1以前では、linkify関数内で正規表現/\*+$/を使用しているため、正規表現のサービス拒否(ReDoS)に対して脆弱です。攻撃者は長いアスタリスクの連続に続いて一致しない文字を供給でき、それにより過剰なバックトラッキングが発生し、サービス拒否状態を引き起こす可能性があります。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
markdown-it: 13.0.0 < 14.1.1
Fixed
Action
Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 12 Feb 2026 · Last source change 12 Feb 2026, 14:41 UTC · CWE-1333 · Inefficient Regular Expression Complexity

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-7037
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    13.0.0 < 14.1.1 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    13.0.0 < 14.1.1 · Fixed: Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-2327 · cve.blacktree.nl