Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-hqv3-xm29-p9hq
Advisory ID github_osv/GHSA-hqv3-xm29-p9hq
Aliases
Summary Duplicate Advisory: Quadratic CPU Exhaustion in `XMLCorpusView._read_xml_fragment()` ## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-vp2x-qp44-57v7. This link is maintained to preserve external references. ## Original 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.
Status Published
Exploitability 0.5
Weighted Severity 5.7
Risk 2.9
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-400 Uncontrolled Resource Consumption
System Score Found at
cvssv3.1 3.7 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-hqv3-xm29-p9hq/GHSA-hqv3-xm29-p9hq.json
cvssv4 6.3 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-hqv3-xm29-p9hq/GHSA-hqv3-xm29-p9hq.json
generic_textual MODERATE
Reference id Reference type URL
https://github.com/nltk/nltk/security/advisories/GHSA-vp2x-qp44-57v7
https://www.vulncheck.com/advisories/nltk-before-3.10.3-quadratic-cpu-exhaustion-via-xmlcorpusview
CVE-2026-81723 https://nvd.nist.gov/vuln/detail/CVE-2026-81723
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-hqv3-xm29-p9hq/GHSA-hqv3-xm29-p9hq.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-hqv3-xm29-p9hq/GHSA-hqv3-xm29-p9hq.json
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.