CVE-2026-54293
What it is
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. Prior to 3.10.0-rc1, nltk.data.load() in NLTK is vulnerable to path traversal via URL-encoded path separators and traversal segments when using the nltk: URL scheme. The unsafe-path regex check is performed before url2pathname() decodes the %xx sequences (a classic decode-after-check / TOCTOU-style flaw), allowing an attacker to bypass the protection documented in NLTK's SECURITY.md and read arbitrary files from the filesystem. While literal traversal strings such as ../../../etc/passwd are correctly blocked, encoded variants such as %2fetc%2fpasswd, %2e%2e%2f..., and ..%2f..%2f slip past the regex and are subsequently decoded into a real filesystem path. This vulnerability is fixed in 3.10.0-rc1.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure.
- Exploit odds
- 0.6% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.6% in the next 30 days (EPSS).
- Severity: 7.5 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.6% · EPSS, next 30 days
- Weakness
- CWE-22 · Path traversal
- Record status
- Modified
Affected
- Nltk < 3.10.0
Attack profile CVSS 3.1 · 7.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-54293.md and follow it. Check whether this project is affected by CVE-2026-54293. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/nltk/nltk/pull/3575
- https://github.com/nltk/nltk/security/advisories/GHSA-p4gq-832x-fm9v
- https://github.com/nltk/nltk/security/advisories/GHSA-p4gq-832x-fm9v
References
- https://github.com/nltk/nltk/pull/3575
- https://github.com/nltk/nltk/security/advisories/GHSA-p4gq-832x-fm9v
- https://access.redhat.com/errata/RHSA-2026:42644
- https://access.redhat.com/errata/RHSA-2026:60520
- https://access.redhat.com/errata/RHSA-2026:65126
- https://access.redhat.com/security/cve/CVE-2026-54293
- https://bugzilla.redhat.com/show_bug.cgi?id=2491486
- https://github.com/nltk/nltk/security/advisories/GHSA-p4gq-832x-fm9v
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54293.json