What’s Vulnerable › Vulnerabilities

CVE-2021-28977

• Severity: medium (CVSS 4.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-06-23 · updated 2026-06-17
• Weakness: CWE-79

Description

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,

Affected products

• GetSimpleCMS: through 3.3.15

References

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

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