Telepresence: Traffic Manager gRPC has no auth — any pod claims arbitrary namespace and intercepts services, receiving victim environment secrets

Exploitation

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

CVSS

8.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

EPSS

• CVE-2026-102340: 0.28% estimated exploitation activity in the next 30 days; percentile 20.82 (FIRST EPSS, 2026-11-10). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Telepresence's Traffic Manager gRPC API (port 8081) requires no authentication. Any pod with cluster-network access to the Traffic Manager can register as a client in an arbitrary managed namespace and create intercepts against services in that namespace, regardless of Kubernetes RBAC. On interception the victim pod's complete container environment (secrets, tokens, API keys) is delivered to the attacker. Tested on HEAD v2.28.0, commit b2231a4.

Details The gRPC server is started with no auth interceptor (pkg/grpc/server/server.go). The connection uses plaintext: `grpc.WithTransportCredentials(insecure.NewCredentials())`. `ArriveAsClient` stores the caller-supplied `Namespace` without verifying the caller is in that namespace. The only gate is whether the namespace is in the Traffic Manager's watchlist (`ManagesNamespace`): ```go // cmd/traffic/cmd/manager/service.go:181-201 func (s *service) ArriveAsClient(..., client *rpc.ClientInfo) (*rpc.SessionInfo, error) { if…

Published by the source

9 Nov 2026, 21:59 UTC

Last modified by the source

9 Nov 2026, 22:15 UTC

Source last checked

10 Nov 2026, 06:45 UTC

1. Revision 2 · amended · 10 Nov 2026

   Amended from osv record GHSA-j8j4-rw65-56r6

2. Revision 1 · created · 9 Nov 2026

   Published from ghsa record GHSA-j8j4-rw65-56r6

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# Patch Next advisory brief: CVE-2026-102340

Advisory: Telepresence: Traffic Manager gRPC has no auth — any pod claims arbitrary namespace and intercepts services, receiving victim environment secrets
IDs: CVE-2026-102340, GHSA-j8j4-rw65-56r6
Record: https://patchnext.com/advisories/cve-2026-102340 (revision 2, source checked 10 Nov 2026, 06:45 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/telepresenceio/telepresence 2.31.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/telepresenceio/telepresence: affected < 2.31.0; fixed in 2.31.0

## Suggested inspection (read-only)
- Go github.com/telepresenceio/telepresence: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/telepresenceio/telepresence.
- 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-j8j4-rw65-56r6 (GitHub-reviewed advisory GHSA-j8j4-rw65-56r6 lists affected ranges: Go github.com/telepresenceio/telepresence >=0 <2.31.0)
- Verified: https://osv.dev/vulnerability/GHSA-j8j4-rw65-56r6 (OSV record GHSA-j8j4-rw65-56r6 lists affected ranges: Go github.com/telepresenceio/telepresence >=0 <2.31.0 (fixed))

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