CVE-2026-48106

Arc Enterprise cluster replication accepts unauthenticated MsgReplicateSync messages, enabling cluster-wide data injection from any TLS-trusted peer

HIGH
8.3
CVSS Score
Published: August 21, 2026 at 10:49 PM UTC
Updated: October 12, 2026 at 04:10 PM UTC
1 product affected across 1 vendorArc

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Severity
HIGH8.3
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Arc is an open, SQL-native time-series database for telemetry. Prior to version 26.06.1, Arc Enterprise's cluster replication receiver at `internal/cluster/replication/receiver.go` validates only the wire-format envelope (length, opcode) of inbound messages. The `MsgReplicateSync` payload itself is accepted without any application-layer authentication — no HMAC, no signature, no per-message nonce. The replication stream is protected at the transport layer by TLS / mTLS, but there is no protection against application-layer message tampering or replay once a peer is on the cluster network. This is fixed in 2026.06.1. Some workarounds are available. Restrict cluster network access to known-trusted peers via strict firewall rules, audit replication logs for unexpected `MsgReplicateSync` traffic, and/or disable cluster mode until the fix is available.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2026.06.1
Affected range stops below 2026.06.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.3HIGHGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-306CWE-345CWE-924

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