GHSA-rh63-9qcf-83gf — jsrsasign
HIGHGHSA-rh63-9qcf-83gf is a high-severity (CVSS 7.5) CWE-203 vulnerability in jsrsasign. 1 public exploit reference exists, so weaponization risk is real. A fix is available for jsrsasign — see the affected versions and patch details below.
Marvin Attack of RSA and RSAOAEP decryption in jsrsasign
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-rh63-9qcf-83gf.
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-rh63-9qcf-83gf 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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
jsrsasignnpmDescription
Versions of the package jsrsasign before 11.0.0 are vulnerable to Observable Discrepancy via the RSA PKCS1.5 or RSAOAEP decryption process. An attacker can decrypt ciphertexts by exploiting the Marvin security flaw. Exploiting this vulnerability requires the attacker to have access to a large number of ciphertexts encrypted with the same key.
Workaround
The vulnerability can be mitigated by finding and replacing RSA and RSAOAEP decryption with another crypto library.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | jsrsasign | all versions | 11.0.0npm install jsrsasign@11.0.0 |
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 jsrsasign, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update jsrsasign to 11.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rh63-9qcf-83gf 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-rh63-9qcf-83gf can be triaged on real exposure rather than presence alone.
Tailored to GHSA-rh63-9qcf-83gf. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Migration Toolkit for Virtualization 2.5 | migration-toolkit-virtualization/mtv-console-plugin-rhel9:2.5.5-3 | RHBA-2024:0928 |
Frequently Asked Questions
Is GHSA-rh63-9qcf-83gf in your dependencies?
O3 Security finds GHSA-rh63-9qcf-83gf across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.