Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%

CVE-2026-88921— MISP: Unescaped HTML Injection in PDF Report Element Rendering

Quick assessment

Affected
MISP MISP
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

MISP 在 组件中存在 HTML 注入漏洞。该组件负责在通过 模块将报告导出为 PDF 时,将 MISP 元素引用(属性、对象和标签)渲染为内联 HTML。 该组件的 、 、 和 方法将用户可控的字段(包括属性类型、属性值、对象名称、对象关系、标签名称、标签颜色及标签文字颜色)直接插入 HTML 模板中,且未进行 HTML 实体编码。因此,具备创建或修改 MISP 属性、对象或标签权限的认证用户,可以在这些字段中嵌入任意 HTML 标记。当包含此类元素的报告被导出为 PDF 时,未经转义的内容会被作为活动 HTM

CVSS 5.1 · Medium

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-88921

Vulnerability Information

Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
MISP: Unescaped HTML Injection in PDF Report Element Rendering
Source: CVE Program / CVE List V5
Vulnerability Description
MISP contains an HTML injection vulnerability in the MISPElementHTMLFormatterTool component, which is responsible for rendering MISP element references (attributes, objects, and tags) into inline HTML during PDF report export via the convert_markdown_to_pdf module. The attribute(), objectAttribute(), object(), and tag() methods interpolated user-controlled fields (attribute type, attribute value, object name, object relation, tag name, tag colour, and tag text colour) directly into HTML templates without applying HTML entity encoding. An authenticated user with the ability to create or modify MISP attributes, objects, or tags could embed arbitrary HTML markup in these fields. When a report containing such elements was exported to PDF, the unescaped content was rendered as live HTML rather than inert text, potentially injecting script tags, breaking the document structure, or altering the visual content of the exported report. Additionally, the attribute() method contained a template with hardcoded sample values ("domain-ip" and "google.com") instead of format placeholders, meaning every plain attribute reference in a PDF displayed the sample text rather than the actual indicator value, constituting a data-integrity defect in the exported document. The vulnerability requires an authenticated actor with write access to MISP elements and a subsequent PDF export of a report referencing those elements. The security impact is primarily to the integrity of the exported document and, depending on the HTML-to-PDF rendering engine, potential execution of injected markup during the conversion step. Version affected: ≤2.5.45
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
在Web页面生成时对输入的转义处理不恰当(跨站脚本)
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
MISP MISP unspecified ~ 2.5.46 -

II. Public POCs for CVE-2026-88921

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-88921

登录查看更多情报信息。

Patches & Fixes for CVE-2026-88921 (1)

IV. Related Vulnerabilities

V. Comments for CVE-2026-88921

No comments yet


Leave a comment