CVE-2021-28977

4.8 mediumEPSS 0.5%

Medium (4.8) in get-simple getsimplecms. EPSS 0.5% chance of exploitation in the next 30 days.

Cross Site Scripting vulnerability in GetSimpleCMS 3.3.16 in admin/upload.php by adding comments or jpg and other file header information to the content of xla, pages, and gzip files,

Severity

CVSS 3.1

4.8 medium

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 43% of CVEs (scores of 2026-10-31)
CWE: CWE-79
Published: 2021-06-23
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

get-simple:getsimplecms

References

https://github.com/GetSimpleCMS/GetSimpleCMS/issues/1336
https://github.com/GetSimpleCMS/GetSimpleCMS/issues/1336

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