CVE-2026-80206

medium Red Hat
CVSS v3 Base Score
5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score
0.3%
Exploitation probability in 30 days
Top 84% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Published: August 26, 2026 (11 days ago)
Last Modified: August 26, 2026
Vendor: Red Hat
Source: REDHAT

Description

NLTK before 3.10.3 contains a regular expression denial of service (ReDoS) vulnerability in the tgrep module. The _tgrep_node_action function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or timeout. An attacker who controls the tgrep pattern (e.g., via tgrep_positions() or tgrep_compile() exposed to external input) can supply a pattern that triggers catastrophic backtracking, causing indefinite CPU saturation that blocks the Python process.

CWE

CWE-1333

Affected Products

Exploit IntelligenceLightspeed CoreOpenShift LightspeedRed Hat Ansible Automation Platform 2Red Hat OpenShift AI (RHOAI)

References

🔗 bugzilla.redhat.com 🔗 www.cve.org 🔗 nvd.nist.gov 🔗 github.com 🔗 www.vulncheck.com