GHSA-hm37-9xh2-q499 is a high-severity (CVSS 7.7) CWE-209 vulnerability in openssh-key-parser. 1 public exploit reference exists, so weaponization risk is real. A fix is available for openssh-key-parser — see the affected versions and patch details below.
Possible leak of key's raw field if declared length is incorrect
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-hm37-9xh2-q499.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-hm37-9xh2-q499 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
openssh-key-parserReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
If a field of a key is shorter than it is declared to be, the parser raises an error with a message containing the raw field value. An attacker able to modify the declared length of a key's sensitive field can thus expose the raw value of that field.
Patches
Upgrade to version 0.0.6, which no longer includes the raw field value in the error message.
Workarounds
N/A
References
N/A
For more information
If you have any questions or comments about this advisory:
- Open an issue in openssh_key_parser
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | openssh-key-parser | all versions | 0.0.6pip install --upgrade 'openssh-key-parser==0.0.6' |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openssh-key-parser, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update openssh-key-parser to 0.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hm37-9xh2-q499 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-hm37-9xh2-q499 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-hm37-9xh2-q499. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-hm37-9xh2-q499 in your dependencies?
O3 Security finds GHSA-hm37-9xh2-q499 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.