Summary
PocketSphinx: Buffer overflows in language and acoustic model loading code
Workarounds
Ensure that the POCKETSPHINX_PATH environment variable is either unset, or set to a directory whose contents are trusted and which cannot be written by untrusted users.
Impact
The trie language model code introduced in PocketSphinx 5prealpha failed to check various boundary conditions when reading the headers of ARPA, DMP, and binary format language model files. In the case of invalid, corrupted or malicious input files, this could lead to stack and heap buffer overflows.
In addition, the acoustic model loading code (which is over 30 years old...) contains numerous instances of sscanf with an unbounded string field which could also lead to stack overflows in the case of corrupt or malicious inputs.
Because PocketSphinx will search the directory given by the POCKETSPHINX_PATH environment variable for acoustic and language model files, if this directory is writable by untrusted users, an attacker could corrupt an existing file or write a malicious one to this directory in order to trigger the vulnerability.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The problem has been corrected in PocketSphinx 5.1.1.
There is no patch currently available for users of Pocketsphinx 5prealpha, who are encouraged to migrate as soon as possible to PocketSphinx 5.1.1.
Frequently Asked Questions
- What is CVE-2026-54559? CVE-2026-54559 is a medium-severity security vulnerability in pocketsphinx (pip), affecting versions < 5.1.1. It is fixed in 5.1.1.
- Which versions of pocketsphinx are affected by CVE-2026-54559? pocketsphinx (pip) versions < 5.1.1 is affected.
- Is there a fix for CVE-2026-54559? Yes. CVE-2026-54559 is fixed in 5.1.1. Upgrade to this version or later.
- Is CVE-2026-54559 exploitable, and should I be worried? Whether CVE-2026-54559 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-54559 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-54559? Upgrade
pocketsphinxto 5.1.1 or later.