CVE-2026-78681

Published: Ago 25, 2026 Last Modified: Ago 25, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,7
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A
HIGH 7,5
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: none
Availability: high

Description

AI Translation Available

NLTK versions before 3.10.3 use xml.etree.ElementTree to parse XML in multiple modules, which honors entity declarations in document DTDs. Attackers can craft XML payloads with nested entity declarations that expand from hundreds of bytes to megabytes in memory, causing denial of service.

776

Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Availability
Potential Impacts:
Dos: Resource Consumption (Other)
Applicable Platforms
Languages: Not Language-Specific, XML
Likelihood of Exploit: Medium
View CWE Details
https://github.com/nltk/nltk/security/advisories/GHSA-97qj-…
https://github.com/nltk/nltk/security/advisories/GHSA-97qj-x29f-37w7
https://www.vulncheck.com/advisories/nltk-before-entity-exp…
https://www.vulncheck.com/advisories/nltk-before-entity-expansion-dos-via-eleme…