CVE-2026-115539
HIGH
MEDIUM
Priority: 0.02
BB Relevance:
65/100
Published: 2026-11-10
Modified: 2026-11-12
First seen: 2026-11-10
Status: active
Attack Surface
Network
Low Complexity
No Interaction
Conf. Impact
Integ. Impact
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
Low
UI:
None
S:
X
AT:
Present
VC:
High
VI:
High
VA:
High
Description
SwarmKit's Cluster-API proxy can overwrite a forwarded client's TLS identity with an intermediary manager's identity. WithMetadataForwardTLSInfo replaces outgoing metadata with a copy of the incoming metadata, discarding the redirect guard's changes when built with grpc-go 1.39 or later. During a short window after a leader change, two proxy hops through managers with inconsistent views of the leader can allow an attacker possessing a valid worker node TLS certificate and private key to obtain a manager node certificate for the attacker's own key, escalating privileges from worker to manager. Applications built with an affected SwarmKit version and grpc-go 1.39 or later are impacted.