CVE-2026-40943Network attack vector

Server crash via session heartbeat race

Published Apr 21, 2026 · Updated Apr 21, 2026

Race condition in Oxia before 0.16.2 allows remote attackers to crash the data server process through rapid KeepAlive requests. The heartbeat() method performs a blocking channel send while holding the session mutex, and KeepAlive() releases its read lock before invoking heartbeat(), leaving a time-of-check-to-time-of-use gap for concurrent close(). Exploitation requires repeated requests as a session expires or closes and can deadlock the session path or panic the entire data server process.

CVSS severity8.7
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in Oxia before 0.16.2 allows remote attackers to crash the data server process through rapid KeepAlive requests. The heartbeat() method performs a blocking channel send while holding the session mutex, and KeepAlive() releases its read lock before invoking heartbeat(), leaving a time-of-check-to-time-of-use gap for concurrent close(). Exploitation requires repeated requests as a session expires or closes and can deadlock the session path or panic the entire data server process.

The record

CVE
CVE-2026-40943
Published
Apr 21, 2026
Updated
Apr 21, 2026
Vendor
Oxia
Product
Oxia
Classifications
CWE-362, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.16.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oxia · Oxiaversion=< 0.16.2

Published CVSS scores

8.7OSVCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.5GitLab Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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