CVE-2026-54559
Received Received - Intake

Buffer Overflow in PocketSphinx Speech Recognition

Vulnerability report for CVE-2026-54559, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-09-14

Last updated on: 2026-09-14

Assigner: GitHub, Inc.

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.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-09-14
Last Modified
2026-09-14
Generated
2026-09-15
AI Q&A
2026-09-14
EPSS Evaluated
N/A
NVD

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
cmusphinx pocketsphinx 5.1.1
cmusphinx pocketsphinx to 5.1.1 (exc)

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-121 A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
CWE-119 The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
CWE-122 A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

CVE-2026-54559 is a buffer overflow vulnerability in PocketSphinx, a speech recognition library. It affects versions before 5.1.1 due to improper validation of language model files and unsafe string handling in acoustic model loaders. Attackers can exploit this by replacing or adding malicious model files in a directory specified by POCKETSPHINX_PATH, leading to memory corruption or crashes.

Detection Guidance

Detecting this vulnerability requires checking the PocketSphinx version and environment configuration. Use 'pocketsphinx_continuous -version' to verify if your version is below 5.1.1. Inspect the POCKETSPHINX_PATH environment variable with 'echo $POCKETSPHINX_PATH' to ensure it points to a trusted directory. Look for suspicious model files in directories referenced by POCKETSPHINX_PATH.

Impact Analysis

If you use PocketSphinx versions prior to 5.1.1, an attacker with write access to POCKETSPHINX_PATH could replace model files with malicious ones. This could cause buffer overflows, memory corruption, or crashes in applications using PocketSphinx. Users of 5prealpha versions have no backported patch and must upgrade to 5.1.1.

Mitigation Strategies

Upgrade PocketSphinx to version 5.1.1 or later immediately. If upgrading is not possible, unset the POCKETSPHINX_PATH environment variable or ensure it points to a trusted, non-writable directory. Remove any untrusted model files from directories that PocketSphinx may search.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-54559. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart