CVE-2026-54700

ConnectBot SSH: Unbounded SSH field lengths can cause excessive memory allocation

State
Published
Severity
6.9 Medium
Published
Oct 13, 2026
Updated
Oct 16, 2026
Reserved
Jun 15, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
4.06.9 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NGitHub_M

Weaknesses

  • CWE-20 Improper Input Validation
  • CWE-789 Memory Allocation with Excessive Size Value

Affected Products

ProductVersions
cbsshconnectbot
  • < 0.3.1Affected

References

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