CVE-2026-62384: NLTK versions before 3.10.2 contain a symlink-based sandbox bypass in FramenetCorpusReader that allows attacke

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-62384 is a high-severity flaw (CVSS 7.5) affecting nltk. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

NLTK versions before 3.10.2 contain a symlink-based sandbox bypass in FramenetCorpusReader that allows attackers to read arbitrary XML files outside the corpus root. Attackers can place symlinks with names containing no path separators inside the corpus subdirectory, which pass the path validation guard and are resolved to files outside the intended corpus root when accessed via frame_by_name(), _lu_file(), or doc() methods.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 49%)
CISA exploited list	No
Weakness	CWE-22
Published	2026-08-22
Last modified	2026-10-14

Publisher (CNA): VulnCheck · Vendor: nltk

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-22 15:16 UTCPublished CVE record published
2026-10-14 13:10 UTCUpdated Record last modified

nltk nltk UPGRADE

Affected: >= 3.10.0 and < 3.10.2

Fixed in: 3.10.2

Safe to downgrade to: a release before 3.10.0

1. Check installed version

apt-cache policy nltk || rpm -q nltk || nltk --version

2. UPGRADE to 3.10.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade nltk

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade nltk

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.10.0 (Debian / Ubuntu)

apt-cache madison nltk sudo apt install nltk=<VERSION_BEFORE_3.10.0> sudo apt-mark hold nltk

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list nltk sudo dnf downgrade nltk-<VERSION_BEFORE_3.10.0> sudo dnf versionlock add nltk

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-62384?

nltk: upgrade to 3.10.2. Exact commands for each OS are on this page.

Is CVE-2026-62384 being exploited?

CVE-2026-62384 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-62384 affect?

CVE-2026-62384 affects nltk. Severity is high (CVSS 7.5). NLTK versions before 3.10.2 contain a symlink-based sandbox bypass in FramenetCorpusReader that allows attackers to read arbitrary XML files outside the corpus root. Attackers can place symlinks with names containing no path separators insi

How urgent is CVE-2026-62384?

Priority 49/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-12252 HIGH 7.8 UPGRADE In nltk/nltk versions 3.9.3 and earlier, five Stanford interface classes (StanfordPOSTagger, StanfordNERTagger
CVE-2026-12259 MEDIUM 6.5 DOWNGRADE In nltk version 3.9.4, the `nltk.downloader.Downloader._download_package()` function writes downloaded package
CVE-2026-12261 MEDIUM 6.5 UPGRADE A vulnerability in `nltk.downloader` in nltk/nltk versions <= 3.9.4 allows for cross-package resource and mode
CVE-2026-12372 LOW 3.7 DOWNGRADE A Server-Side Request Forgery (SSRF) vulnerability exists in nltk/nltk versions 3.9.4 and the current develop
CVE-2026-71513 HIGH 8.8 UPGRADE NLTK before 3.10.3 contains a remote code execution vulnerability in AllowlistUnpickler that validates only th

References

← Back to latest CVEs