VulnerabilityPublished 13 Aug 2026Updated 29 Oct 2026

CVE-2026-59924: Mistune · Arbitrary File Read via Include directive path traversal

Affects jupyterlabSource GCVE Database

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Authoritative record:CVE-2026-59924· Medium 5.9

Not known to be exploited · CVSS 5.9 Medium : upgrade to 4.6.1 when convenient.

Data as of 30 Oct 2026, 09:02 UTC

CVSS 3.1 base score

5.9Medium

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 4.6.1

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

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

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade jupyterlab to 4.6.1.

Affected software

Product	Affected	Fixed in
Homebrewjupyterlab`pkg:brew/jupyterlab`Other threats	Affected >=1.2.0 <4.6.1	Fixed in 4.6.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in jupyterlab version 4.6.1. Users should upgrade to this version or later to remediate the vulnerability. The recommended fix involves validating the resolved include path to ensure it remains within an allowed base directory before opening the file. Until patched, avoid processing untrusted markdown files with the Include directive enabled.

Description

A path traversal vulnerability exists in the mistune library's Include directive when processing markdown files using md.read(). This flaw allows crafted include paths to access files outside the intended markdown directory. The issue arises because the resolved file path is not verified to remain within a trusted base directory, enabling traversal sequences like ../ to escape the intended folder. Applications that process untrusted markdown with this directive enabled may inadvertently expose sensitive files. The vulnerability affects jupyterlab versions from 1.2.0 up to but not including 4.6.1. A fix is available in version 4.6.1.

Impact

Exploitation of this vulnerability allows an attacker to read arbitrary files accessible to the application process by including them via crafted markdown include directives. This can lead to disclosure of sensitive information depending on the files accessible to the running process. The vulnerability does not allow code execution or modification, but the confidentiality impact is high. The attack requires processing of untrusted markdown files with the Include directive enabled.

Summary

CVE-2026-59924 describes a path traversal vulnerability in mistune's Include directive used in markdown processing. The vulnerability occurs in the Include.parse() method where user-supplied relative paths are joined and normalized without restricting the final resolved path to a trusted base directory. This allows an attacker to craft include directives with traversal sequences (e.g., ../../../example.txt) that access files outside the intended markdown directory. The vulnerability affects jupyterlab versions >=1.2.0 and <4.6.1. The issue is mitigated by validating that the resolved path remains within an allowed directory before file access. A patch fixing this issue is included in jupyterlab version 4.6.1.

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Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 09:02 UTC

Technical details

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