CVE-2026-44896Network attack vector

Cross-site scripting via unescaped Figure attributes

Published May 26, 2026 · Updated May 26, 2026

Cross-site scripting in Lepture Mistune 3.2.0 and earlier allows remote attackers to execute browser script via a crafted Figure directive. The render_figure() function in src/mistune/directives/image.py appends figclass and figwidth values directly to class and style attributes without HTML escaping, bypassing HTMLRenderer(escape=True). Exploitation requires an application to enable the Figure directive, render attacker-controlled Markdown, and have another user view the generated HTML.

CVSS severity5.3
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Lepture Mistune 3.2.0 and earlier allows remote attackers to execute browser script via a crafted Figure directive. The render_figure() function in src/mistune/directives/image.py appends figclass and figwidth values directly to class and style attributes without HTML escaping, bypassing HTMLRenderer(escape=True). Exploitation requires an application to enable the Figure directive, render attacker-controlled Markdown, and have another user view the generated HTML.

The record

CVE
CVE-2026-44896
Published
May 26, 2026
Updated
May 26, 2026
Vendor
Lepture
Product
Mistune
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 2026CVE publishedPublication date reported by the CVE source.
  2. May 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 3.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Lepture · Mistuneversion=<= 3.2.0

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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