CVE-2026-59930
published 2026-07-08CVE-2026-59930: Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the toc plugin and TableOfContents directive generate heading IDs as…
PriorityP418medium4.3CVSS 3.1
AVNACLPRNUIRSUCNILAN
EPSS
0.19%
8.8th percentile
Mistune 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.
Affected
27 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| lepture | mistune | < 3.3.0 | 3.3.0 |
| mistune_project | mistune | < 3.3.0 | 3.3.0 |
| mistune_project | mistune | >= 0 < 3.3.0 | 3.3.0 |
| mta | mta-solution-server-rhel9 | — | — |
| rhoai | odh-pipeline-runtime-datascience-cpu-py312-rhel9 | — | — |
| rhoai | odh-pipeline-runtime-minimal-cpu-py312-rhel9 | — | — |
| rhoai | odh-pipeline-runtime-pytorch-cuda-py312-rhel9 | — | — |
| rhoai | odh-pipeline-runtime-pytorch-llmcompressor-cuda-py312-rhel9 | — | — |
| rhoai | odh-pipeline-runtime-pytorch-rocm-py312-rhel9 | — | — |
| rhoai | odh-pipeline-runtime-tensorflow-cuda-py312-rhel9 | — | — |
| rhoai | odh-pipeline-runtime-tensorflow-rocm-py312-rhel9 | — | — |
| rhoai | odh-th06-cpu-torch210-py312-rhel9 | — | — |
| rhoai | odh-th06-cpu-torch291-py312-rhel9 | — | — |
| rhoai | odh-th06-cuda130-torch210-py312-rhel9 | — | — |
| rhoai | odh-th06-cuda130-torch291-py312-rhel9 | — | — |
| rhoai | odh-th06-rocm64-torch291-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-datascience-cpu-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-minimal-cpu-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-minimal-cuda-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-minimal-rocm-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-pytorch-cuda-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-pytorch-rocm-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-tensorflow-cuda-py312-rhel9 | — | — |
| rhoai | odh-workbench-jupyter-tensorflow-rocm-py312-rhel9 | — | — |
CVSS provenance
nvdv3.14.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
vendor_redhat4.3MEDIUM
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GHSA
Mistune toc / TableOfContents directive: heading IDs use predictable `toc_N` numbering with no slugification, allowing collision with attacker-controlled `id="toc_N"` content
ghsa·2026-07-20
CVE-2026-59930 [MEDIUM] CWE-1284 Mistune toc / TableOfContents directive: heading IDs use predictable `toc_N` numbering with no slugification, allowing collision with attacker-controlled `id="toc_N"` content
Mistune toc / TableOfContents directive: heading IDs use predictable `toc_N` numbering with no slugification, allowing collision with attacker-controlled `id="toc_N"` content
## Summary
**Type:** Predictable identifier generation. The `toc` plugin and `TableOfContents` directive both default to generating heading IDs of the form `toc_1`, `toc_2`, `toc_3`, ... with no input-derived component. An attacker who can place a heading anywhere in the document can predict which `toc_N` ID it will receive, and can inject HTML elsewhere (in a non-heading context) that uses the same `id="toc_N"` to either (a) shadow the legitimate heading anchor, breaking same-page navigation, or (b) collide with CSS or JavaScript that targets `#toc_N` selectors, redirecting click handlers and styling to attacker-ch
Red Hat
mistune: Mistune: Same-page navigation redirection due to predictable heading IDs
vendor_redhat·2026-07-08·CVSS 4.3
CVE-2026-59930 [MEDIUM] CWE-79 mistune: Mistune: Same-page navigation redirection due to predictable heading IDs
mistune: Mistune: Same-page navigation redirection due to predictable heading IDs
Mistune 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.
A flaw was found in Mistune, a Python Markdown parser. The table of contents (toc) plugin and TableOfContents directive generate heading identifiers (IDs) as predictable values (e.g., toc_N) without properly processing the heading text. This allows an attacker to control content with a colliding ID, which can
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-59930 python-mistune: Mistune: Same-page navigation redirection due to predictable heading IDs [fedora-all]
bugzilla·2026-07-09·CVSS 4.3
CVE-2026-59930 [MEDIUM] CVE-2026-59930 python-mistune: Mistune: Same-page navigation redirection due to predictable heading IDs [fedora-all]
CVE-2026-59930 python-mistune: Mistune: Same-page navigation redirection due to predictable heading IDs [fedora-all]
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.
Mistune 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.
Bugzilla
CVE-2026-59930 python-mistune: Mistune: Same-page navigation redirection due to predictable heading IDs [epel-all]
bugzilla·2026-07-09·CVSS 4.3
CVE-2026-59930 [MEDIUM] CVE-2026-59930 python-mistune: Mistune: Same-page navigation redirection due to predictable heading IDs [epel-all]
CVE-2026-59930 python-mistune: Mistune: Same-page navigation redirection due to predictable heading IDs [epel-all]
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.
Mistune 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.
Bugzilla
CVE-2026-59930 mistune: Mistune: Same-page navigation redirection due to predictable heading IDs
bugzilla·2026-07-08·CVSS 4.3
CVE-2026-59930 [MEDIUM] CVE-2026-59930 mistune: Mistune: Same-page navigation redirection due to predictable heading IDs
CVE-2026-59930 mistune: Mistune: Same-page navigation redirection due to predictable heading IDs
Mistune 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.
2026-07-08
Published