Core FTP 2.0 build 653 PBSZ Unauthenticated Denial of Service
Published Apr 5, 2026
8.7
HIGHCVSS 4.0
EPSS 0.47%
Description
Core FTP 2.0 build 653 contains a denial of service vulnerability in the PBSZ command that allows unauthenticated attackers to crash the service by sending a malformed command with an oversized buffer. Attackers can send a PBSZ command with a payload exceeding 211 bytes to trigger an access violation and crash the FTP server process.
Affected products
-
- Version 2.0StatusaffectedConstraints-
- Version
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
1 other source (NVD) ▾
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Apr 6, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
Apr–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 0.47% (0.00466) | 38.09th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.47% (0.00466) | 36.58th | v5 (v2026.06.15) |
| Apr 6, 2026 | 0.04% (0.00043) | 13.23th | v4 (v2025.03.14) |
References (4)
- http://coreftp.com/server/download/archive/CoreFTPServer653.exe product
- http://www.coreftp.com/ product
- https://www.exploit-db.com/exploits/46532 exploitVDB Entry
- https://www.vulncheck.com/advisories/core-ftp-build-653-pbsz-unauthenticated-denial-of-service third-party-advisoryThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| http://coreftp.com/server/download/archive/CoreFTPServer653.exe | product | |
| http://www.coreftp.com/ | product | |
| https://www.exploit-db.com/exploits/46532 | exploitVDB Entry | |
| https://www.vulncheck.com/advisories/core-ftp-build-653-pbsz-unauthenticated-denial-of-service | third-party-advisoryThird Party Advisory |
Change history (0)
No recorded changes yet.