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Medium 6.9Published Oct 13, 2026

CVE-2026-54700ConnectBot SSH: Unbounded SSH field lengths can cause excessive memory allocation

Updated under an hour ago ()

Does this affect you?

It affects connectbot cbssh. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
6.9 MEDIUM (v4.0, CNA)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
Weakness (CWE)
CWE-20, CWE-789
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
GitHub_M
NVD analysis
Deferred
Record last updated
Oct 16, 2026
First seen by InfoSec Signals
Oct 13, 2026

Affected products

Affected products
connectbot cbssh
connectbot:cbssh (from the name)
before 0.3.1
CNA record

References

  • x-refsource-confirm
  • x-refsource-misc
  • x-refsource-misc
  • x-refsource-misc

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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