CVE-2026-115353
Mistune before 3.3.0 Path Traversal via include Directive
Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to read arbitrary files by supplying relative or absolute paths. Attackers can submit markdown containing include directives referencing ../ sequences or absolute paths to embed sensitive files like credentials or environment data in rendered HTML.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Mistune before 3.3.0 Path Traversal via include Directive
Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to read arbitrary files by supplying relative or absolute paths. Attackers can submit markdown containing include directives referencing ../ sequences or absolute paths to embed sensitive files like credentials or environment data in rendered HTML.
- Record
CVE-2026-115353- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N - CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-04
EUVDEUVD-2026-108422
Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to read arbitrary files by supplying relative or absolute paths. Attackers can submit markdown containing include directives referencing ../ sequences or absolute paths to embed sensitive files like credentials or environment data in rendered HTML.
- Record
EUVD-2026-108422- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N - Updated
- 2026-11-04
GitHub AdvisoriesGHSA-pfvv-4pq6-mx74
Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that...
Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to read arbitrary files by supplying relative or absolute paths. Attackers can submit markdown containing include directives referencing ../ sequences or absolute paths to embed sensitive files like credentials or environment data in rendered HTML.
- Record
GHSA-pfvv-4pq6-mx74- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
NVD
Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to read arbitrary files by supplying relative or absolute paths. Attackers can submit markdown containing include directives referencing ../ sequences or absolute paths to embed sensitive files like credentials or environment data in rendered HTML.
- Record
CVE-2026-115353- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-04
OSV
Mistune before 3.3.0 Path Traversal via include Directive
Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to read arbitrary files by supplying relative or absolute paths. Attackers can submit markdown containing include directives referencing ../ sequences or absolute paths to embed sensitive files like credentials or environment data in rendered HTML.
- Record
CVE-2026-115353- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N - Weakness
- CWE-22
- Updated
- 2026-11-05
OSVDEBIAN-CVE-2026-115353
Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to read arbitrary files by supplying relative or absolute paths. Attackers can submit markdown containing include directives referencing ../ sequences or absolute paths to embed sensitive files like credentials or environment data in rendered HTML.
- Record
DEBIAN-CVE-2026-115353- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-05
OSVUBUNTU-CVE-2026-115353
Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to read arbitrary files by supplying relative or absolute paths. Attackers can submit markdown containing include directives referencing ../ sequences or absolute paths to embed sensitive files like credentials or environment data in rendered HTML.
- Record
UBUNTU-CVE-2026-115353- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N - CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:12407-1 No score
python313-mistune-3.4.0-2.1 on GA media
These are all security issues fixed in the python313-mistune-3.4.0-2.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12407-1- Updated
- 2026-11-04
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mistuneDebian:12 |
All versions, plus listed versions 2.0.4-12.0.4-23.0.2-13.0.2-23.1.3-13.1.4-13.3.4-13.4.0-1 |
None known |
mistuneDebian:13 |
All versions, plus listed versions 3.1.3-13.1.4-13.3.4-13.4.0-1 |
None known |
mistuneDebian:14 |
All versions, plus listed versions 3.1.3-13.1.4-13.3.4-13.4.0-1 |
None known |
mistuneUbuntu:16.04:LTS |
All versions, plus listed versions 0.6-20.7.1-1 |
None known |
mistuneUbuntu:18.04:LTS |
All versions, plus listed versions 0.7.4-10.8-10.8.1-10.8.3-2 |
None known |
mistuneUbuntu:20.04:LTS |
All versions, plus listed versions 0.8.4-10.8.4-2 |
None known |
mistuneUbuntu:22.04:LTS |
All versions, plus listed versions 0.8.4-40.8.4-52.0.0-1+really0.8.4-1 |
None known |
mistuneUbuntu:24.04:LTS |
All versions, plus listed versions 2.0.4-23.0.2-1 |
None known |
mistuneUbuntu:26.10 |
All versions, plus listed versions 3.1.4-1 |
None known |
mistuneUbuntu:26.04:LTS |
All versions, plus listed versions 3.1.3-13.1.4-1 |
None known |
python-mistuneopenSUSE:Tumbleweed From an advisory covering 4 CVEs |
before 3.4.0-2.1 | 3.4.0-2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | EUVD, NVD, OSV | |
| references | CVE List | |
| affected, aliases, facts, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-115353 is a critical vulnerability (CVSS 9.2) in Lepture Mistune, published October 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.39%, the 33rd percentile. No source names a fixed version.
References
github.com/lepture/mistune/security/advisories/GHSA-9jjx-3hq3-hx4j
vulncheck.com/advisories/mistune-before-3.3.0-path-traversal-via-include-directive
nvd.nist.gov/vuln/detail/CVE-2026-115353
security-tracker.debian.org/tracker/CVE-2026-115353