GHSA-j3q4-gmj4-mj95 is a critical-severity (CVSS 9.8) CWE-384 vulnerability in rdiffweb. 1 public exploit reference exists, so weaponization risk is real. A fix is available for rdiffweb — see the affected versions and patch details below.
rdiffweb vulnerable to account access via session fixation
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-j3q4-gmj4-mj95.
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-j3q4-gmj4-mj95 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 378,567 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
rdiffwebReal-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
rdiffweb prior to 2.4.7 fails to invalidate session cookies on logout, leading to session fixation and allowing an attacker to access a users account. After logging in and logging out, the application continues to use the preauthentication cookies. The cookies remain the same after closing the browser and after password reset. The same cookies are reassigned for additional user logins which can lead to session fixation. An attacker can gain unauthorized access to the account of users who are using the same browser as long as a single session cookie persists on that browser once the attacker obtains a session cookie through another attack. This issue is patched in version 2.4.7. There are no known workarounds.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | rdiffweb | all versions | 2.4.7pip install --upgrade 'rdiffweb==2.4.7' |
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 rdiffweb, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rdiffweb to 2.4.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j3q4-gmj4-mj95 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-j3q4-gmj4-mj95 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-j3q4-gmj4-mj95. 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-j3q4-gmj4-mj95 in your dependencies?
O3 Security finds GHSA-j3q4-gmj4-mj95 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.