CVE-2026-129126
C-Kermit before 11.1.515 Heap Buffer Overflow via putsrv() Packet Decoding
CVSS Score
8.1
EPSS Score
0.0%
EPSS Percentile
0th
C-Kermit before 11.1.515 contains a heap buffer overflow vulnerability in putsrv() in ckcfns.c that allows malicious peers to write past the srvcmd buffer by sending crafted packets. Attackers can use Kermit repeat-count compression in server command, GET, or file-header packets to write attacker-chosen bytes beyond the heap buffer on servers or receiving instances.
| CWE | CWE-122 |
| Vendor | openkermit |
| Product | c-kermit |
| Published | Nov 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
OpenKermit / C-Kermit
0 < 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/37e54720779237897bc6887efac42fe138817897 github.com: https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515 github.com: https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckcfns.c#L461 vulncheck.com: https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-heap-buffer-overflow-via-putsrv-packet-decoding
Credits
John Goerzen John Goerzen