CVEvulnerability
CVE-2026-78681
8.7 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-08-25
- Last modified
- 2026-10-12
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 8.7 HIGH — CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
- CVSS 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-776
Description
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.
Affected configurations
• nltk nltk (< 3.10.3)
Related
Weakness · CWE (1)
- CWE-776 Improper Restriction of Recursive Entity References in DTDs weakness
References
- https://github.com/nltk/nltk/security/advisories/GHSA-97qj-x29f-37w7 Exploit, Vendor Advisory
- https://www.vulncheck.com/advisories/nltk-before-entity-expansion-dos-via-elementtree Third Party Advisory