CVE-2026-62388 NLTK before 3.10.0 Insecure Default Configuration in pathsec.py
Attackers can bypass path traversal and deserialization protections in NLTK because security checks are disabled by default, requiring an upgrade to enforce them.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-62388?
CVE-2026-62388 is a high-severity vulnerability in nltk, published on 22 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
NLTK versions before 3.10.0 default to ENFORCE=False in pathsec.py, causing all security validation functions to emit warnings instead of raising exceptions. Attackers can bypass path traversal and pickle deserialization protections by exploiting the disabled security controls that are only active when manually enabled.
Weakness: CWE-1188
Which versions are affected by CVE-2026-62388?
3 open source packages ship an affected version, including nltk. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
nltk PyPI | All versions | 3.10.0 |
nltk PyPI | All versions | 3.10.0 |
nltk PyPI | All versions | 3.10.0 |
Products include Nltk Nltk.
How do I fix CVE-2026-62388?
Upgrade nltk to 3.10.0 or later.
Is CVE-2026-62388 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-62388 exists.
Other vulnerabilities in nltk
- CVE-2026-0848 Arbitrary Code Execution in NLTK StanfordSegmenter via Untrusted JAR Loading
- CVE-2025-14009 Zip Slip Vulnerability in nltk/nltk Leading to Remote Code Execution
- CVE-2026-78683 NLTK before 3.10.0 Remote Code Execution via Unsafe Pickle Deserialization
- CVE-2026-79657 NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization
- CVE-2026-79675 NLTK before 3.10.3 JVM Argument Injection via Per-Call Options
Sources
Also known as DEBIAN-CVE-2026-62388, ECHO-7cc1-59c5-b855, GHSA-p3m8-78j2-g5p3, MINI-9353-p28q-mfcp, PYSEC-2026-3722, UBUNTU-CVE-2026-62388.