PatchTheCVECVE-2020-7747: This affects all versions of package lightning-server
CVE-2020-7747 is a medium-severity flaw (CVSS 6.3) affecting lightning. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
This affects all versions of package lightning-server. It is possible to inject malicious JavaScript code as part of a session controller.
Why this priority
- Public exploit reference
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 6.3 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | Required |
| EPSS exploit chance | 0.9% (top 41%) |
| CISA exploited list | No |
| Weakness | CWE-79 |
| Published | 2020-10-20 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2020-7747?
lightning: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2020-7747 being exploited?
CVE-2020-7747 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2020-7747 affect?
CVE-2020-7747 affects lightning. Severity is medium (CVSS 6.3). This affects all versions of package lightning-server. It is possible to inject malicious JavaScript code as part of a session controller.
How urgent is CVE-2020-7747?
Priority 42/100. Public exploit reference