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CVE-2026-129126

8.1, high

OpenKermit C-Kermit Heap-based Buffer Overflow Vulnerability

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

Description

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.

Details

Vendor
OpenKermit
Product
C-Kermit
Weakness
CWE-122 (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:N/S:U/C:H/I:H/A:H

References 5

Patches and fixes 1

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-2026-129126 in your network?

This page tells you how dangerous CVE-2026-129126 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.

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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.