CVE-2026-70626: NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local att

Q: How do I fix CVE-2026-70626?

nltk: upgrade to 3.9.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-70626 being exploited?

CVE-2026-70626 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-70626 affect?

CVE-2026-70626 affects nltk. Severity is medium (CVSS 6.2). NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not a

Q: How urgent is CVE-2026-70626?

Priority 29/100. Public exploit reference

Routine

MEDIUM 6.2UPGRADE

CVE-2026-70626 is a medium-severity flaw (CVSS 6.2) affecting nltk. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place symlinks inside the corpus root to access files outside the intended boundary.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.2 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 90%)
CISA exploited list	No
Weakness	CWE-59
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: < 3.9.4

Fixed in: 3.9.4

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 3.9.4 (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.

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-2026-70626?

nltk: upgrade to 3.9.4. Exact commands for each OS are on this page.

Is CVE-2026-70626 being exploited?

CVE-2026-70626 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-2026-70626 affect?

CVE-2026-70626 affects nltk. Severity is medium (CVSS 6.2). NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not a

How urgent is CVE-2026-70626?

Priority 29/100. Public exploit reference

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References

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