VulnerabilityPublished 11 Nov 2026

CVE-2026-115350: python-mistune security update

Affects python-mistuneSource GCVE Database

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Mentioned vulnerabilities

Authoritative record:CVE-2026-115350· Medium 5.3

Not known to be exploited · CVSS 5.3 Medium : upgrade to 2.0.4-4.oe2403sp4 when convenient.

Data as of 11 Nov 2026, 14:32 UTC

CVSS 4.0 base score

5.3Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (VulnCheck)	CVSS 4.0	5.3
CNA (VulnCheck)	CVSS 3.1	6.1

Patch: Available – fixed in 2.0.4-4.oe2403sp4

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: Passive
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: Low
Subsequent system integrity: Low
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Subsequent System.
Subsequent system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Subsequent System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Oct 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 11 Nov 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 python-mistune to 2.0.4-4.oe2403sp4.

Affected software

Product	Affected	Fixed in
openEuler 24.03-LTS-SP4python-mistune`pkg:rpm/openEuler/python-mistune&distro=openEuler-24.03-LTS-SP4`Other threats	Affected <2.0.4-4.oe2403sp4	Fixed in 2.0.4-4.oe2403sp4

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AI-suggested

A patch is available in python-mistune version 2.0.4-4.oe2403sp4 that addresses these vulnerabilities. Users should upgrade to this fixed version to remediate the issues. No additional mitigation steps are indicated by the vendor advisory.

Description

python-mistune versions before 2.0.4-4.oe2403sp4 contain multiple vulnerabilities including cross-site scripting (XSS) and path traversal in the Include directive. These flaws allow attackers to read arbitrary local files and inject malicious HTML or scripts into rendered Markdown output. The issues are fixed in version 2.0.4-4.oe2403sp4.

Impact

Successful exploitation can lead to disclosure of sensitive local files and execution of malicious scripts in the context of rendered Markdown, resulting in cross-site scripting attacks. This can compromise confidentiality and potentially affect the security of applications using vulnerable versions of python-mistune for Markdown rendering.

Summary

The python-mistune package prior to version 2.0.4-4.oe2403sp4 is affected by several security vulnerabilities related to its Include directive. Specifically, CVE-2026-115350 describes a cross-site scripting vulnerability where included .html, .xhtml, or .htm files are emitted as raw block_html tokens, enabling script execution if escape=False is set. Additional path traversal vulnerabilities (CVE-2026-115353, CVE-2026-115354, CVE-2026-115355) allow attackers to read arbitrary files by supplying relative or absolute paths in include directives, potentially exposing sensitive data such as credentials or environment information. These vulnerabilities also enable injection of unescaped HTML or script content, even when escape=True is set, through error messages or included file contents. The vulnerabilities are resolved in python-mistune version 2.0.4-4.oe2403sp4.

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What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Nov 2026, 14:32 UTC

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