Skip to content
EXYS
Back to the CVEs

CVE-2026-129122

7.5, high

OpenKermit C-Kermit Out-of-Bounds Write Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab)
CVSS
7.5, high high CVSS v3.1
EPSS, next 30 days
n/a
Exploitation
No public evidence
Published
13 Nov 2026yesterday

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.

Details

Vendor
OpenKermit
Product
C-Kermit
Weakness
CWE-787 (opens in a new tab)
Status
Deferred
Updated
13 Nov 2026
Assigner
disclosure@vulncheck.com

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

References 6

Patches and fixes 2

Advisories 1

Other references 3

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other OpenKermit CVEs

Every OpenKermit CVE we hold

Same vendor in what we hold, not a known link between the flaws.

Beyond this page

Is CVE-2026-129122 in your network?

This page tells you how dangerous CVE-2026-129122 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

  • EXYS7600 OCELOT

    Find it before attackers do

    Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2026-129122 comes with the devices to patch.

    Learn more about EXYS7600 OCELOT

  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

    Learn more about EXYS7950 KONDRA
Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 14 Nov 2026, not the live upstream state.