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

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-91990— Tornado before 6.5.8 Memory Amplification DoS via multipart

Quick assessment

Affected
tornadoweb tornado
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.

Tornado 在 6.5.8 之前存在一个内存放大漏洞，位于 函数中。该函数在验证 限制之前就会对 multipart 数据进行切分。攻击者可以构造包含大量分片的 multipart 请求，从而创建大型临时列表，耗尽服务器内存，导致服务拒绝（DoS）攻击。

CVSS 7.5 · High

Possible ATT&CK Techniques 1 AI

T1499 · Endpoint Denial of Service
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-91990

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
Tornado before 6.5.8 Memory Amplification DoS via multipart
Source: CVE Program / CVE List V5
Vulnerability Description
Tornado before 6.5.8 contains a memory amplification vulnerability in parse_multipart_form_data that splits multipart data before validating the max_parts limit. Attackers can send crafted multipart requests with many parts to create large transient lists, exhausting server memory and causing denial of service.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
不加限制或调节的资源分配
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
tornadoweb tornado 0 ~ 6.5.8 -

II. Public POCs for CVE-2026-91990

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-91990

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-91990 (2)

Same Patch Batch · tornadoweb · 2026-09-15 · 6 CVEs total

CVE-2023-54397 7.5 HIGH Tornado before 6.3.3 HTTP Request Smuggling via Content-Length
CVE-2024-14029 7.5 HIGH Tornado before 6.4.1 HTTP Request Smuggling via Transfer-Encoding
CVE-2026-91992 5.9 MEDIUM Tornado before 6.5.7 Credential Leak via Handle Reuse
CVE-2026-91991 5.4 MEDIUM Tornado before 6.5.8 Cookie Attribute Injection via Capitalized kwargs
CVE-2024-58384 5.4 MEDIUM Tornado before 6.4.1 CRLF Injection via CurlAsyncHTTPClient

IV. Related Vulnerabilities

Same product: tornado
Same vendor: tornadoweb
Same weakness: CWE-770

V. Comments for CVE-2026-91990

No comments yet

Leave a comment