OpenKermit
C-Kermit before 11.1.515 Heap Buffer Overflow via putsrv() Packet Decoding
Not on CISA's list of exploited flaws, and not in the news we track.
CVE-2026-129126Critical9.2
Reading the vendor advisory
Black Shard's team can check your exposure to CVE-2026-129126 and take the fix off your plate.
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.
Black Shard's team can check your exposure, take a fix off your plate or step in on a live incident.
Severity
9.2of 10, critical
Updated 14 Nov 2026, 12:44 UTC, 33 of 36 sources answering.
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