CVE-2021-3828
python3-nltk: nltk is vulnerable to Inefficient Regular Expression Complexity
CVE-2021-3828 is fixed in 2 products on 1 platform, first by python-nltk 3.2.5-1ubuntu0.1+esm1, released September 27, 2021. It is not reported as exploited. Patch Radar priority: Routine.
Routine
CVSS
n/a
Medium
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0159
75th percentile
nltk is vulnerable to Inefficient Regular Expression Complexity
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| python-nltk · Ubuntu 18.04.6 LTS (bionic) | 3.2.5-1ubuntu0.1+esm1 | python-nltk 3.2.5-1ubuntu0.1+esm1 | Sep 27, 2021 |
| python3-nltk · Ubuntu 18.04.6 LTS (bionic) | 3.2.5-1ubuntu0.1+esm1 | python3-nltk 3.2.5-1ubuntu0.1+esm1 | Sep 27, 2021 |
| python3-nltk · Ubuntu 20.04 LTS (focal) | 3.4.5-2ubuntu0.1~esm1 | python3-nltk 3.4.5-2ubuntu0.1~esm1 | Sep 27, 2021 |
| python3-nltk · Ubuntu 22.04.1 LTS (jammy) | 3.6.5-1 | python3-nltk 3.6.5-1 | Sep 27, 2021 |
| python3-nltk · Ubuntu 24.10 (oracular) | 3.6.5-1 | python3-nltk 3.6.5-1 | Jan 16, 2026 |
| python3-nltk · Ubuntu 25.04 (plucky) | 3.6.5-1 | python3-nltk 3.6.5-1 | Jan 16, 2026 |
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