CVE-2026-0848

nltk: NLTK versions <=3.9.2 are vulnerable to arbitrary code execution due to improper input validation in the StanfordSegm...

CVE-2026-0848 is fixed in 3 products on 1 platform, first by DEBIAN-CVE-2026-0848, released March 5, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

Urgent
CVSS
10.0
critical
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0084
58th percentile

NLTK versions <=3.9.2 are vulnerable to arbitrary code execution due to improper input validation in the StanfordSegmenter module. The module dynamically loads external Java .jar files without verification or sandboxing. An attacker can supply or replace the JAR file, enabling the execution of arbitrary Java bytecode at import time. This vulnerability can be exploited through methods such as model poisoning, MITM attacks, or dependency poisoning, leading to remote code execution. The issue arises from the direct execution of the JAR file via subprocess with unvalidated classpath input, allowing malicious classes to execute when loaded by the JVM.

Where it's fixed

ProductFixed inFixReleased
Linux
nltk · Debian 14 3.9.3-1 DEBIAN-CVE-2026-0848 Mar 5, 2026
python-nltk · Ubuntu 18.04.6 LTS (bionic) 3.2.5-1ubuntu0.1+esm4 python-nltk 3.2.5-1ubuntu0.1+esm4 Mar 20, 2026
python3-nltk · Ubuntu 18.04.6 LTS (bionic) 3.2.5-1ubuntu0.1+esm4 python3-nltk 3.2.5-1ubuntu0.1+esm4 Mar 20, 2026
python3-nltk · Ubuntu 20.04 LTS (focal) 3.4.5-2ubuntu0.1~esm4 python3-nltk 3.4.5-2ubuntu0.1~esm4 Mar 20, 2026
python3-nltk · Ubuntu 22.04.1 LTS (jammy) 3.7-1ubuntu0.1~esm2 python3-nltk 3.7-1ubuntu0.1~esm2 Mar 20, 2026
python3-nltk · Ubuntu 24.04.5 LTS (noble) 3.8.1-1ubuntu0.1~esm2 python3-nltk 3.8.1-1ubuntu0.1~esm2 Mar 20, 2026
python3-nltk · Ubuntu 26.04.1 LTS (resolute) 3.9.2-1ubuntu0.1~esm2 python3-nltk 3.9.2-1ubuntu0.1~esm2 Mar 20, 2026

Patch Radar data is free to use with attribution. Terms and how to credit it.

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.