CVE-2026-54700

medium

Description

ConnectBot SSH Client Library is written in Kotlin with Kaitai Struct and KStateMachine. Prior to 0.3.1, the SSH protocol parser trusts attacker-controlled inner byte lengths and element counts without verifying that they fit in the containing packet. A malicious or compromised SSH server can return a small malformed packet whose oversized declarations cause the Kaitai Struct Java runtime to attempt excessive allocation or repeated parsing before detecting truncated input. The general transport path requires a client connection but no authentication or optional feature; malformed SSH-agent messages additionally require SSH agent forwarding. The issue can raise an uncaught OutOfMemoryError and terminate the application process, with no demonstrated confidentiality or integrity impact. This issue is fixed in version 0.3.1.

References

https://github.com/connectbot/cbssh/security/advisories/GHSA-ch3q-cw5r-f4hg

https://github.com/connectbot/cbssh/releases/tag/v0.3.1

https://github.com/connectbot/cbssh/pull/194

https://github.com/connectbot/cbssh/commit/a08421fbe7cf8b72fa60fb8b2f98fb465dc43fd9

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-98838

Details

Source: Mitre, NVD

Published: 2026-10-13

Updated: 2026-10-13

Risk Information

CVSS v2

Base Score: 5.8

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:P

Severity: Medium

CVSS v3

Base Score: 9.1

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

Severity: Critical

CVSS v4

Base Score: 6.9

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: Medium