CVE-2026-129123
C-Kermit 8.0.200 before 11.1.515 FTP Client Buffer Overflow via PBSZ and ADAT Replies
CVSS Score
8.8
EPSS Score
0.0%
EPSS Percentile
0th
C-Kermit 8.0.200 before 11.1.515 contains a buffer overflow vulnerability in getreply() in ckcftp.c that allows malicious FTP servers to overwrite client memory by sending overlong security replies. Attackers controlling or intercepting an FTP server can send long PBSZ replies after AUTH TLS, or long ADAT replies in GSSAPI, Kerberos 4, and SRP builds, overflowing the static reply_buf with attacker-controlled bytes.
| CWE | CWE-120 |
| Vendor | openkermit |
| Product | c-kermit |
| Published | Nov 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
OpenKermit / C-Kermit
8.0.200 < 11.1.515
References
github.com: https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p github.com: https://github.com/OpenKermit/ckermit/commit/39ab009a365b97632e9975e1266fa618c4bdc59f github.com: https://github.com/OpenKermit/ckermit/commit/bec28a4d544031fa07a07aacba3df5dd1202ef69 github.com: https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515 github.com: https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckcftp.c#L11161 vulncheck.com: https://www.vulncheck.com/advisories/c-kermit-8.0.200-before-11.1.515-ftp-client-buffer-overflow-via-pbsz-and-adat-replies
Credits
John Goerzen John Goerzen