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GHSA-5gqc-qhrj-9xw8

HighCVSS 8.7 / 10
Published Apr 14, 2026·Last modified May 5, 2026
Affected Components(0)

No affected components available

Description

Summary

A race condition between session heartbeat processing and session closure can cause the server to panic with send on closed channel. The heartbeat() method uses a blocking channel send while holding a mutex, and under specific timing with concurrent close() calls, this can lead to either a deadlock (channel buffer full) or a panic (send on closed channel after TOCTOU gap in KeepAlive).

Impact

A remote client can trigger a server crash by sending rapid KeepAlive requests while a session is expiring or being closed. This is a denial-of-service vulnerability that crashes the entire data server process.

All versions are affected.

Details

In oxiad/dataserver/controller/lead/session.go, the heartbeat() method performs a blocking s.heartbeatCh <- true send. If the channel buffer is full (size 1), this blocks while holding the session mutex, preventing close() from acquiring the lock to close the channel — a deadlock.

Additionally, in session_manager.go, KeepAlive() releases the session manager's read lock before calling heartbeat(), creating a TOCTOU window where the session can be removed and closed between the lookup and the heartbeat call.

Patches

Fixed by changing heartbeat() to use a non-blocking select with a default case, and by holding the session manager read lock through the entire KeepAlive() operation.

Workarounds

No workaround available.

Risk Scores
Base Score
8.7

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence
6.6

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
0.20%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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