CVE-2026-59924: Mistune: Arbitrary File Read via Include directive path traversal
Noroxi assessment
Priority: Monitor (action score 23/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.46% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: lepture mistune 3.3.0.
Low priority for now. Upgrade to lepture mistune 3.3.0 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Include.parse() joins and normalizes user-supplied include paths without verifying that the result remains within the intended markdown directory, allowing crafted include paths to access files outside that directory when markdown files are processed using md.read(). This issue is fixed in version 3.3.0.
- Published
- Jul 8, 2026
- Updated
- Oct 25, 2026
- EPSS
- 0.4% · 40th percentile
- CWE
- CWE-22
Report tools
Action score
23
Low priority for now.
- CVSS
- 23 / 40 · 5.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 5.9
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| mistune project | mistune | cpe:2.3:a:mistune_project:mistune |
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
lepture mistune
- < 3.3.0affected
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- mistune project mistunebefore 3.3.0
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | mistune | from 0 | — |
| openSUSE:Leap 16.0 | python-mistune | before 3.1.3-160000.5.1 | 3.1.3-160000.5.1 |
| PyPI | mistune | before 3.3.0 | 3.3.0 |
| SUSE:Linux Enterprise Server 16.0 | python-mistune | before 3.1.3-160000.5.1 | 3.1.3-160000.5.1 |
Same product
mistune project: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-59928Mistune block_parser: quadratic-time parsing on long lists of repeated reference-link definitions30Monitor
- CVE-2026-59925inline_parser: quadratic-time parsing on long runs of `**x**` and `***x***` emphasis pairs30Monitor
- CVE-2026-59922Mistune plugins/formatting: quadratic-time parsing on long runs of `~~x~~`, `==x==`, and `^^x^^` markers (strikethrough / mark / insert)30Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-44899May 26, 2026 · Mistune Image Directive CSS Injection Vulnerability24Monitor
- ← EarlierCVE-2026-59923Jul 8, 2026 · Mistune: XSS via percent-encoded javascript URI bypass in safe_url()24Monitor
- Later →CVE-2026-59926Jul 8, 2026 · Mistune: XSS via unescaped class option in Admonition directive21Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| lepture mistune | 3.3.0 · description | Vendor (CNA) |
| opensuse:python-mistune | 3.1.3-160000.5.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| PyPI:mistune | 3.3.0 | Package registry (OSV) |
| suse:python-mistune | 3.1.3-160000.5.1 · SUSE:Linux Enterprise Server 16.0 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd-secondary
Root cause
A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.
The bug in code
The whole CWE-22 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const file = path.join(ROOT, req.query.name);
res.sendFile(file);Fixed
const file = path.resolve(ROOT, req.query.name);
if (!file.startsWith(ROOT + path.sep)) {
return res.sendStatus(400);
}
res.sendFile(file);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Path TraversalCAPEC-126likelihood: High · Very High
- Using Slashes and URL Encoding Combined to Bypass Validation LogicCAPEC-64likelihood: High · High
- Manipulating Web Input to File System CallsCAPEC-76likelihood: High · Very High
- Using Escaped Slashes in Alternate EncodingCAPEC-78likelihood: High · High
- Using Slashes in Alternate EncodingCAPEC-79likelihood: High · High
ATT&CK techniques
—
Change log (1)
- Fix✗ → ✓
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References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.