mistune — security advisory
Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.render_token() can exceed Python's recursion limit and raise RecursionError, allowing crafted Markdown to crash a parsing process. This issue is fixed in version 3.3.3
- Products
- mistune
- Affected versions
- 2.0.4-1, 2.0.4-2, 3.0.2-1, 3.0.2-2, 3.1.3-1, 3.1.4-1, 3.3.4-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-76098
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 09:03 UTC · Revision 1
Source evidence
Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.render_token() can exceed Python's recursion limit and raise RecursionError, allowing crafted Markdown to crash a parsing process. This issue is fixed in version 3.3.3
osv:DEBIAN-CVE-2026-76098
mistune
Fixed versions: Not specified
mistune
Fixed versions: Not specified
mistune
Fixed versions: Not specified
Complete source record
{
"id": "4c1b275e8b89f4bae8e5590959dc50dce211a43f431fdbb0a24c76fb7ce97eac",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-76098",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-76098",
"summary": "Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.render_token() can exceed Python's recursion limit and raise RecursionError, allowing crafted Markdown to crash a parsing process. This issue is fixed in version 3.3.3",
"evidence": "osv:DEBIAN-CVE-2026-76098",
"products": [
{
"name": {
"value": "mistune",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.0.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.0.4-2",
"evidence": "/affected/0/versions"
},
{
"value": "3.0.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.0.2-2",
"evidence": "/affected/0/versions"
},
{
"value": "3.1.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.1.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.4-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "mistune",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.1.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.1.4-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.3.4-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "mistune",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.1.3-1",
"evidence": "/affected/2/versions"
},
{
"value": "3.1.4-1",
"evidence": "/affected/2/versions"
},
{
"value": "3.3.4-1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-76098",
"aliases": [
"DEBIAN-CVE-2026-76098"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "mistune",
"purl": "pkg:deb/debian/mistune?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"2.0.4-1",
"2.0.4-2",
"3.0.2-1",
"3.0.2-2",
"3.1.3-1",
"3.1.4-1",
"3.3.4-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-76098.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "mistune",
"purl": "pkg:deb/debian/mistune?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"3.1.3-1",
"3.1.4-1",
"3.3.4-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-76098.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "mistune",
"purl": "pkg:deb/debian/mistune?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"3.1.3-1",
"3.1.4-1",
"3.3.4-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-76098.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-13T09:47:42.156628675Z",
"provider": "osv",
"upstream": [
"CVE-2026-76098"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-76098"
]
},
"related_cves": [
{
"value": "CVE-2026-76098",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 307590,
"published_at": "2026-08-24T20:17:19.33+00:00"
}