---
id: CVE-2026-102339
title: >-
  Telepresence: Tunnel endpoint accepts caller-supplied session ID with no
  ownership proof — active client sessions hijackable
summary: >-
  Telepresence enables local development against a remote Kubernetes or
  OpenShift cluster. Prior to 2.31.0, the Traffic Manager Tunnel gRPC streaming
  endpoint parses a session ID from the first bytes of a caller-controlled
  message in pkg/t…
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N'
cvssSource: cna
cwe:
  - CWE-639
vendor: telepresenceio
product: telepresence
affected:
  - telepresence < 2.31.0
published: '2026-11-04'
updated: '2026-11-04'
sourceUpdated: '2026-11-04T20:35:34.030Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-102339'
references:
  - url: >-
      https://github.com/telepresenceio/telepresence/security/advisories/GHSA-6j3h-rp73-6rvf
    label: >-
      https://github.com/telepresenceio/telepresence/security/advisories/GHSA-6j3h-rp73-6rvf
  - url: 'https://github.com/telepresenceio/telepresence/pull/4217'
    label: 'https://github.com/telepresenceio/telepresence/pull/4217'
  - url: >-
      https://github.com/telepresenceio/telepresence/commit/1312482488b771742dbedd3015f9a81a27532de6
    label: >-
      https://github.com/telepresenceio/telepresence/commit/1312482488b771742dbedd3015f9a81a27532de6
  - url: >-
      https://github.com/telepresenceio/telepresence/commit/36458b65a010d2b316af48cd90e193ba190785d9
    label: >-
      https://github.com/telepresenceio/telepresence/commit/36458b65a010d2b316af48cd90e193ba190785d9
  - url: 'https://github.com/telepresenceio/telepresence/releases/tag/v2.31.0'
    label: 'https://github.com/telepresenceio/telepresence/releases/tag/v2.31.0'
tags:
  - cve.org
ingestedAt: '2026-11-05T21:36:00.563Z'
epss: 0.00287
epssPercentile: 0.21329
---

## Overview

Telepresence enables local development against a remote Kubernetes or OpenShift cluster. Prior to 2.31.0, the Traffic Manager Tunnel gRPC streaming endpoint parses a session ID from the first bytes of a caller-controlled message in pkg/tunnel/message.go and passes it to state.Tunnel without verifying that the caller owns the active session. An attacker who obtains a valid active session ID through log leakage, cluster-internal channels, or the unauthenticated ArriveAsClient endpoint can attach a routed tunnel to that session and gain its network routing capabilities. UUID4 session IDs make cold brute force impractical. This vulnerability is fixed in 2.31.0.

## Affected

- `telepresence < 2.31.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.