---
title: "CVE-2026-0846\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2026-0846?format=md
keywords: index, follow
---

# CVE-2026-0846

Publication date 9 March 2026

Last updated 27 May 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**8.6 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2026-0846?format=md#impact-score)

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## Description

A vulnerability in the `filestring()` function of the `nltk.util` module in
nltk version 3.9.2 allows arbitrary file read due to improper validation of
input paths. The function directly opens files specified by user input
without sanitization, enabling attackers to access sensitive system files
by providing absolute paths or traversal paths. This vulnerability can be
exploited locally or remotely, particularly in scenarios where the function
is used in web APIs or other interfaces that accept user-supplied input.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| nltk | 26.04 LTS resolute | Fixed 3.9.2-1ubuntu0.1~esm2  Ubuntu Pro |
| 25.10 questing | Ignored end of life, was needed |
| 24.04 LTS noble | Fixed 3.8.1-1ubuntu0.1~esm2  Ubuntu Pro |
| 22.04 LTS jammy | Fixed 3.7-1ubuntu0.1~esm2  Ubuntu Pro |
| 20.04 LTS focal | Fixed 3.4.5-2ubuntu0.1~esm4  Ubuntu Pro |
| 18.04 LTS bionic | Fixed 3.2.5-1ubuntu0.1+esm4  Ubuntu Pro |
| 16.04 LTS xenial | Fixed 3.1-1ubuntu0.1+esm4 |
| 14.04 LTS trusty | Fixed 2.0~b9-0ubuntu4.1~esm6  Ubuntu Pro |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2026-0846?format=md#patch-details)

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### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| nltk | * Upstream:   [1fc6269](https://github.com/nltk/nltk/commit/1fc626969f013bba104a40e5e760b9d67b2994ea) * Upstream:   [5c46f3d](https://github.com/nltk/nltk/commit/5c46f3dac7e0eb10ee7d9f7be9fe732b0ec0af25) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

8.6 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | High |
  | Integrity impact | Low |
  | Availability impact | Low |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 8.6 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-0846)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-0846)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-0846)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-0846)

### Related Ubuntu Security Notices (USN)

+ [USN-8302-1](https://usn.ubuntu.com/USN-8302-1)
+ NLTK vulnerabilities
+ 25 May 2026

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-0846>
* <https://huntr.com/bounties/007b84f8-418e-4300-99d0-bf504c2f97eb>
* <https://github.com/nltk/nltk/pull/3485>
* <https://github.com/nltk/nltk/commit/1fc626969f013bba104a40e5e760b9d67b2994ea>
* <https://github.com/nltk/nltk/commit/5c46f3dac7e0eb10ee7d9f7be9fe732b0ec0af25>