CVE-2026-129122
Received
Received - Intake
Buffer Overflow in C-Kermit Telnet Client
Vulnerability report for CVE-2026-129122, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-11-13
Last updated on: 2026-11-13
Assigner: VulnCheck
Description
Description
C-Kermit 6.0.192 before 11.1.515 contains a buffer overflow vulnerability in tn_snenv() in ckctel.c that allows malicious Telnet servers to corrupt client memory via crafted NEW-ENVIRON SEND subnegotiation. Malicious or machine-in-the-middle servers can send oversized variable names before authentication, overflowing a 16-byte stack buffer and a miscomputed heap buffer to corrupt stack and heap memory.
CVSS Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| OpenKermit | C-Kermit | From 6.0.192 (inc) to 11.1.515 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
