GHSA-xc27-f9q3-4448 is a low-severity (CVSS 3.3) Path Traversal vulnerability in hyper-bump-it. 1 public exploit reference exists, so weaponization risk is real. A fix is available for hyper-bump-it — see the affected versions and patch details below.
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in hyper-bump-it
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-xc27-f9q3-4448.
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-xc27-f9q3-4448 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 377,333 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
hyper-bump-itReal-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
Summary
hyper-bump-it reads a file glob pattern from the configuration file. That is combined with the project root directory to construct a full glob pattern that is used to find files that should be edited. These matched files should be contained within the project root directory, but that is not checked. This could result in changes being written to files outside of the project.
The default behaviour of hyper-bump-it is to display the planned changes and prompt the user for confirmation before editing any files. However, the configuration file provides a field that can be used cause files to be edited without displaying the prompt.
Details
The vulnerability is present in
That code joins the project root directory with a string read from the configuration file without checking if the final path is located outside the project root directory.
The following configuration file contents would cause hyper-bump-it to replace every instance of "hello" in every file adjacent to the project root directory with "world". The line setting show_confirm_prompt to false is not required, but will result in the user file edits to occur without the user having a chance to reject the changes (The fact that changes happened would still be displayed).
[hyper-bump-it]
current_version = "1.2.3"
show_confirm_prompt=false
[[hyper-bump-it.files]]
file_glob = "../*"
search_format_pattern = "hello"
replace_format_pattern = "world"
Patches
A fix that been released as part of v0.5.1. The changes can be view as part of PR #307.
Workarounds
Users that are unable to update from vulnerable versions, executing hyper-bump-it with the --interactive command line argument will ensure that all planned changes are displayed and prompt the user for confirmation before editing any files, even if the configuration file contains show_confirm_prompt=true.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | hyper-bump-it | all versions | 0.5.1pip install --upgrade 'hyper-bump-it==0.5.1' |
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 hyper-bump-it, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update hyper-bump-it to 0.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xc27-f9q3-4448 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-xc27-f9q3-4448 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-xc27-f9q3-4448. 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-xc27-f9q3-4448 in your dependencies?
O3 Security finds GHSA-xc27-f9q3-4448 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.