Auth bypass in Telepresenceio Telepresence
CVE-2026-102339
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.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Telepresenceio Telepresence — versions < 2.31.0
Weakness classification (CWE)
References
- https://github.com/telepresenceio/telepresence/commit/1312482488b771742dbedd3015f9a81a27532de6
- https://github.com/telepresenceio/telepresence/commit/36458b65a010d2b316af48cd90e193ba190785d9
- https://github.com/telepresenceio/telepresence/pull/4217
- https://github.com/telepresenceio/telepresence/releases/tag/v2.31.0
- https://github.com/telepresenceio/telepresence/security/advisories/GHSA-6j3h-rp73-6rvf
Frequently asked questions
- What is CVE-2026-102339?
- CVE-2026-102339 is a high-severity vulnerability in Telepresenceio Telepresence, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 8.2/10. Published 2026-11-04.
- How severe is CVE-2026-102339?
- High severity. CVSS v3 base score is 8.2 out of 10.