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TI-2026-71767 Aliases CVE-2026-54700

ConnectBot SSH library allows excessive memory allocation

Priority LOW 37CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Active
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-789.

Summary

ConnectBot cbssh before 0.3.1 and the Maven package org.connectbot.sshlib:sshlib from 0 through 0.3.0 are affected. The SSH parser trusts attacker-controlled byte lengths and element counts without checking they fit in the containing packet (CWE-20). A malicious or compromised SSH server can send a small malformed packet that causes excessive memory allocation and an uncaught OutOfMemoryError that terminates the application. Only a client connection is needed, with no authentication.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0037 31st percentileScored 2026-11-07
Fix Fixed cbssh (connectbot): 0.3.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
connectbotcbsshbefore 0.3.10.3.1Patch availableCNA
—org.connectbot.sshlib:sshlib (Maven)up to 0.3.0—No fix listedGHSA-ch3q-cw5r-f4hg
  • cbssh Vendorconnectbot Affected before 0.3.1 Fixed in 0.3.1 Patch available CNA
  • org.connectbot.sshlib:sshlib (Maven) Vendor— Affected up to 0.3.0 Fixed in — No fix listed GHSA-ch3q-cw5r-f4hg

Remediation

Upgrade cbssh to version 0.3.1, which fixes the issue. The sources list no fixed version for org.connectbot.sshlib:sshlib.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA cbssh (connectbot) Fixed in 0.3.1

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-54700
  2. 2026-10-14 Priority changed: MEDIUM → LOW
  3. 2026-10-18 CISA SSVC decision points changed
  4. 2026-11-06 Affected versions changed · Red Hat
  5. 2026-11-06 CVSS score added · Red Hat

References

Other 5

  • TI-2023-26623 The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6… CVSS 3.1MEDIUM 5.9
  • TI-2026-71766 Integer overflow in ConnectBot SSH DER private-key parsing CVSS 4.0MEDIUM 6.7

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences