Mistune toc / TableOfContents directive: heading IDs use predictable `toc_N` numbering with no slugification, allowing collision with attacker-controlled `id="toc_N"` content

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-59930
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-08 17:17:28 UTC
Updated2026-07-08 17:17:28 UTC
DescriptionMistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the toc plugin and TableOfContents directive generate heading IDs as predictable toc_N values without slugifying the heading text, allowing attacker-controlled id="toc_N" content to collide with generated anchors and redirect same-page navigation, CSS selectors, or JavaScript handlers. This issue is fixed in version 3.3.0.

Risk And Classification

Primary CVSS: v3.1 4.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Problem Types: CWE-345 | CWE-1284 | CWE-345 CWE-345: Insufficient Verification of Data Authenticity | CWE-1284 CWE-1284: Improper Validation of Specified Quantity in Input

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary4.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
3.1CNADECLARED4.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Lepture Mistune affected < 3.3.0 Not specified

References

ReferenceSourceLinkTags
github.com/lepture/mistune/releases/tag/v3.3.0 [email protected] github.com
github.com/lepture/mistune/security/advisories/GHSA-2hm2-hc3v-44h9 [email protected] github.com
github.com/lepture/mistune/commit/c4093c4742ed0d10d9332fb8edb455869b7b581b [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report