---
title: "CVE-2026-54559\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-2026-54559?format=md
keywords: index, follow
---

# CVE-2026-54559

Publication date 14 September 2026

Last updated 16 September 2026

---

Ubuntu priority

**Medium**

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

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## Description

PocketSphinx is a small speech recognizer. Prior to 5.1.1, the trie
language-model loaders in src/lm/ngram\_model\_trie.c do not adequately
validate boundary conditions in ARPA, DMP, and binary format headers, and
the acoustic-model loaders in src/mdef.c and src/util/bio.c use sscanf with
unbounded string fields. Loading an invalid, corrupted, or malicious
language or acoustic model can therefore cause stack or heap buffer
overflows and memory corruption. An attacker who can write to a directory
selected by POCKETSPHINX\_PATH can replace or add a model file that
PocketSphinx later loads; users of PocketSphinx 5prealpha have no
backported patch and must migrate to the fixed release. This issue is fixed
in version 5.1.1.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| pocketsphinx | 26.04 LTS resolute | Needs evaluation |
| 24.04 LTS noble | Needs evaluation |
| 22.04 LTS jammy | Needs evaluation |
| 20.04 LTS focal | Needs evaluation |
| 18.04 LTS bionic | Needs evaluation |
| 16.04 LTS xenial | Needs evaluation |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v4.0

**Base score**

6.9 · Medium

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Attack requirements | None |
  | Privileges required | None |
  | User interaction | None |
  | Vulnerable system - Confidentiality impact | None |
  | Vulnerable system - Integrity impact | Low |
  | Vulnerable system - Availability impact | None |
  | Subsequent system - Confidentiality impact | None |
  | Subsequent system - Integrity impact | None |
  | Subsequent system - Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 6.9 · Medium |
  | Base + Threat score | - |
  | Base + Environmental score | - |
  | Base + Threat + Environmental score | - |

**Vector:** CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-54559)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-54559)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-54559)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-54559)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-54559>
* <https://github.com/cmusphinx/pocketsphinx/commit/2a3c03788a9973eff548664334fb781e9f4ad4a5>
* <https://github.com/cmusphinx/pocketsphinx/releases/tag/v5.1.1>
* <https://github.com/cmusphinx/pocketsphinx/security/advisories/GHSA-56r5-2p2f-7cxp>