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Vulnerabilities

Vulnerability · CVE-2021-47904

PhreeBooks 5.2.3 contains an authenticated file upload vulnerability in the Image Manager that allows remote code execution.

Published Jan 23, 2026 · catalog updated Jul 28, 2026 · Phreesoft PhreeBooks

Last checked Nov 5, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2021-47904. EPSS is 0.71%. Act only if a listed version of Phreesoft PhreeBooks is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High8.7
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.71%
Remediation
Vendor / distro source
Affected products
vendor Phreesoft PhreeBooks 5.2.3

PhreeBooks 5.2.3 contains an authenticated file upload vulnerability in the Image Manager that allows remote code execution. Attackers can upload a malicious PHP web shell by exploiting unrestricted file type uploads to gain command execution on the server.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Phreesoft PhreeBooks 5.2.35.2.3

How to fix CVE-2021-47904

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2021-47904. EPSS is 0.71%. Act only if a listed version of Phreesoft PhreeBooks is installed.

Which versions are affected?

Compare what you have installed with Phreesoft PhreeBooks 5.2.3 5.2.3. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.71%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jan 23, 2026 · EUVD

    Detected

    PhreeBooks 5.2.3 contains an authenticated file upload vulnerability in the Image Manager that allows remote code execution. Attackers can upload a malicious PHP web shell by exploiting unrestricted file type uploads to gain command execution on the server.

  2. Jul 28, 2026 · EUVD

    Updated

    PhreeBooks 5.2.3 contains an authenticated file upload vulnerability in the Image Manager that allows remote code execution. Attackers can upload a malicious PHP web shell by exploiting unrestricted file type uploads to gain command execution on the server.

Sources

  • CVE.orgVulnerability recordCVE-2021-47904

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-47904

    30-day exploitation probability 0.71%

    first.org
  • EUVDVulnerability recordEUVD-2026-4274

    PhreeBooks 5.2.3 contains an authenticated file upload vulnerability in the Image Manager that allows remote code execution. Attackers can upload a malicious PHP web shell by exploiting unrestricted file type uploads to gain command execution on the server.

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 5, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 5, 2026
  • CVE.orgNov 4, 2026
  • EUVDNov 2, 2026