CVE-2026-80205

NLTK versions before 3.10.0 contain a regular expression denial of service vulnerability in Text.findall() and TokenSearcher.findall() methods that accept user-supplied regular expressions without validation or timeout. Attackers can supply crafted regex patterns that cause catastrophic backtracking, resulting in indefinite CPU saturation and denial of service to all users of the Python process.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/nltk/nltk/security/advisories/GHSA-rrv8-h7p8-rx55	Exploit Vendor Advisory
https://www.vulncheck.com/advisories/nltk-before-3.10.0-redos-via-text-findall-unvalidated-regex	Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/09/01/3

Configurations

Configuration 1 (hide)

cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-08-26 11:16

Updated : 2026-09-03 05:15

NVD link : CVE-2026-80205

Mitre link : CVE-2026-80205

CVE.ORG link : CVE-2026-80205

JSON object : View

Products Affected

nltk

nltk

CWE

CWE-1333

Inefficient Regular Expression Complexity

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