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

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-81723— NLTK before 3.10.3 Quadratic CPU Exhaustion via XMLCorpusView

Quick assessment

Affected
nltk nltk
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.

NLTK 3.10.3 之前的版本中， 存在一个导致 CPU 二次方耗尽（quadratic CPU exhaustion）的漏洞。该函数在每次读取 1 KiB 的数据块时，都会重新扫描之前累积的 XML 片段。攻击者可以提供格式错误的 XML 语料库文件，导致严重的 CPU 资源消耗，从而通过受影响的读取器（如 ）引发拒绝服务（DoS）问题。

CVSS 3.7 · Low

Possible ATT&CK Techniques 1 AI

T1005 · Data from Local System
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-81723

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
NLTK before 3.10.3 Quadratic CPU Exhaustion via XMLCorpusView
Source: CVE Program / CVE List V5
Vulnerability Description
NLTK versions before 3.10.3 contain a quadratic CPU exhaustion vulnerability in XMLCorpusView._read_xml_fragment() that rescans accumulated XML fragments on every 1 KiB block read. Attackers can provide malformed XML corpus files to cause severe CPU consumption and denial of service through affected readers like BNCCorpusReader.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Source: CVE Program / CVE List V5
Vulnerability Type
未加控制的资源消耗(资源穷尽)
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
nltk nltk 0 ~ 3.10.3 -

II. Public POCs for CVE-2026-81723

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-81723

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-81723 (2)

Same Patch Batch · nltk · 2026-08-27 · 6 CVEs total

CVE-2026-81722 7.5 HIGH nltk PorterStemmer before 3.10.3 Quadratic-time DoS
CVE-2026-81727 7.1 HIGH NLTK before 3.10.3 Hardlink File Overwrite via downloader
CVE-2026-81726 7.0 HIGH NLTK through 3.10.3 Path Traversal via Model-Artifact APIs
CVE-2026-81724 5.3 MEDIUM NLTK before 3.10.3 Denial of Service via Uncontrolled Recursion
CVE-2026-81725 3.7 LOW NLTK before 3.10.3 Regular Expression Denial of Service via Pl196xCorpusReader

IV. Related Vulnerabilities

Same product: nltk
Same vendor: nltk
Same weakness: CWE-400

V. Comments for CVE-2026-81723

No comments yet

Leave a comment