ConnectBot SSH Client Library: Excessive allocation and integer overflow in DER private-key parsing

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.7 · CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-54697: 0.13% estimated exploitation activity in the next 30 days; percentile 2.21 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The DER parser used for application-supplied private keys did not safely validate encoded length values before converting them to Int values or allocating arrays. A malformed private-key file could encode a length that overflowed or wrapped around, or request an allocation much larger than the available input. This could cause parsing errors or an uncaught OutOfMemoryError, potentially terminating the application process. Details The issue was in DerReader.readLength() and primitive readers such as readInteger(). readLength() previously accepted up to 127 length octets and accumulated them into an Int: This permitted integer overflow. For example: - 0x100000001 wrapped to 1. - 0x80000000 wrapped to Int.MINVALUE. Primitive readers then allocated memory based on the resulting value without first checking it against the remaining input: A six-byte DER value declaring a 1 GiB INTEGER caused an immediate OutOfMemoryError when tested with a constrained JVM heap. Because…

Published by the source

12 Jun 2026, 21:02 UTC

Last modified by the source

8 Jul 2026, 17:35 UTC

Source last checked

26 Oct 2026, 16:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vc8p-8pxg-rfwg

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# Patch Next advisory brief: CVE-2026-54697

Advisory: ConnectBot SSH Client Library: Excessive allocation and integer overflow in DER private-key parsing
IDs: CVE-2026-54697, GHSA-vc8p-8pxg-rfwg
Record: https://patchnext.com/advisories/cve-2026-54697 (revision 1, source checked 26 Oct 2026, 16:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.connectbot.sshlib:sshlib: affected <= 0.3.0

## Suggested inspection (read-only)
- Maven org.connectbot.sshlib:sshlib: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.connectbot.sshlib:sshlib.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-vc8p-8pxg-rfwg (GitHub-reviewed advisory GHSA-vc8p-8pxg-rfwg lists affected ranges: Maven org.connectbot.sshlib:sshlib >=0 <=0.3.0)

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