PatchTheCVECVE-2021-22849: Hyweb HyCMS-J1 backend editing function does not filter special characters
CVE-2021-22849 is a medium-severity flaw (CVSS 4.6) affecting hycms-j1. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Hyweb HyCMS-J1 backend editing function does not filter special characters. Users after log-in can inject JavaScript syntax to perform a stored XSS (Stored Cross-site scripting) attack.
Why this priority
- No elevated risk signals yet
A fixed release or distro patch exists.
Risk facts
| CVSS score | 4.6 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | Required |
| EPSS exploit chance | 0.5% (top 56%) |
| CISA exploited list | No |
| Weakness | CWE-79 |
| Published | 2021-01-22 |
| 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-2021-22849?
hycms-j1: upgrade to newer than 7.4.3. Exact commands for each OS are on this page.
Is CVE-2021-22849 being exploited?
CVE-2021-22849 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-2021-22849 affect?
CVE-2021-22849 affects hycms-j1. Severity is medium (CVSS 4.6). Hyweb HyCMS-J1 backend editing function does not filter special characters. Users after log-in can inject JavaScript syntax to perform a stored XSS (Stored Cross-site scripting) attack.
How urgent is CVE-2021-22849?
Priority 27/100. No elevated risk signals yet.
Related CVEs
- CVE-2021-22847 HIGH 8.8 UPGRADE Hyweb HyCMS-J1's API fail to filter POST request parameters