GHSA-3ccg-x393-96v8 is a critical-severity (CVSS 9.1) CWE-521 vulnerability in code.vikunja.io/api. No vendor fix is recorded yet; mitigation options are listed below.
Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-3ccg-x393-96v8.
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-3ccg-x393-96v8 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
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 The application allows users to set weak passwords (e.g., 1234, password) without enforcing minimum strength requirements. Additionally, active sessions remain valid after a user changes their password.
An attacker who compromises an account (via brute-force or credential stuffing) can maintain persistent access even after the victim resets their password.
Details
- Weak passwords are accepted during registration and password change.
- No minimum length or strength validation is enforced.
- After changing the password, previously issued session tokens remain valid.
- No forced logout occurs across active sessions.
Attack scenario:
Attacker guesses or obtains weak credentials. Logs in and obtains active session token. Victim changes password. Attacker continues accessing the account using the old session.
Steps to Reproduce
1. Register using a weak password (e.g., 12345678 ). 2. Log in and Password Change functionality. 3. Change account password with single character (e.g., 1 or a ) 4. Reuse the old session. 5. Observe that access is still granted.
Impact
- Persistent account takeover
- Unauthorized access to sensitive data
- Increased brute-force success probability
- Elevated risk for administrative accounts
The combination of weak password controls and improper session invalidation significantly increases both exploitability and impact.
Recommendation Password Policy Improvements:
- Enforce strong password policies – Require passwords to be 8–16+ characters with a mix of uppercase, lowercase, numbers, and special characters.
- Block common passwords – Use a blacklist of commonly used and breached passwords.
- Use secure hashing – Store passwords using strong salted hashing algorithms like bcrypt or Argon2.
- Enable account lockout – Limit failed login attempts to reduce brute-force risk.
- Educate users – Promote strong password practices and phishing awareness.
Session Management Fix:
- Invalidate all active sessions upon password change
- Revoke refresh tokens (if applicable)
- Implement token/session versioning
- Regenerate session IDs after credential updates
- Log and notify users of password change events
Implementing both controls will significantly reduce the risk of persistent account compromise.
<img width="1918" height="907" alt="Weak Password Policy Combined with Persistent Sessions After Password Change POC" src="https://github.com/user-attachments/assets/f188b69b-0472-4d2c-aeda-c145384c99ef" />A fixed version is available at https://github.com/go-vikunja/vikunja/releases/tag/v2.0.0.
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-3ccg-x393-96v8 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-3ccg-x393-96v8 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-3ccg-x393-96v8. 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-3ccg-x393-96v8 in your dependencies?
O3 Security finds GHSA-3ccg-x393-96v8 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.