CVE-2026-40943: Github.com/oxia db/oxia Oxia Affected By Server Crash Vulnerability

HIGH
Advisory Identifier: GHSA-5gqc-qhrj-9xw8
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CWE-362
Published
Advisory Summary

CVE-2026-40943 is a HIGH oxia affected by server crash vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting Github.com/oxia db/oxia libraries in the Go ecosystem. The issue involves oxia affected by server crash via race condition in session heartbeat handling. Remediation is available by upgrading affected packages to version 0.16.2.

CVE-2026-40943 at a Glance

CVE Identifier CVE-2026-40943
GHSA Identifier GHSA-5gqc-qhrj-9xw8
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Product Github.com/oxia db/oxia
Package Ecosystem Go
Published Date
Last Updated

How to Fix CVE-2026-40943

To remediate this vulnerability, upgrade all affected Github.com/oxia db/oxia dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/oxia-db/oxia fixed: 0.16.2 
Upgrade github.com/oxia-db/oxia to 0.16.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/oxia-db/oxia

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-40943, inspect your project dependencies for Github.com/oxia db/oxia:

inspect dependencies for github.com/oxia-db/oxia

Analyze the terminal output to locate any version of Github.com/oxia db/oxia in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.16.2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), where the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. In Github.com/oxia db/oxia, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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.

CVE-2026-40943 Affected Github.com/oxia db/oxia Versions

1 component(s)
Fixed Versions:
0.16.2
Product / Package Ecosystem Affected Versions Fixed Version
github.com/oxia-db/oxia
golang/github.com/oxia-db/oxia
Go
< 0.16.2
0.16.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/oxia-db/oxia/security/advisories/GHSA-5gqc-qhrj-9xw8
NVD — CVE-2026-40943 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40943
Github.com/oxia db/oxia Source Repository REPOSITORY
https://github.com/oxia-db/oxia

Frequently Asked Questions

What is CVE-2026-40943?
CVE-2026-40943 is a security vulnerability in Github.com/oxia db/oxia involving Oxia affected by server crash via race condition in session heartbeat handling under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which Github.com/oxia db/oxia versions are affected?
Affected versions include releases prior to 0.16.2 across affected packages: github.com/oxia-db/oxia.
What version fixes CVE-2026-40943?
Upgrading to 0.16.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/oxia-db/oxia affected?
Yes, github.com/oxia-db/oxia is affected in releases prior to 0.16.2. Upgrade your dependency to 0.16.2 or later.
What CWE is associated with CVE-2026-40943?
CVE-2026-40943 is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.).
How can I check Go dependencies for CVE-2026-40943?
Run the dependency tree command: 'inspect dependencies for github.com/oxia-db/oxia'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5gqc-qhrj-9xw8",
  "modified" : "2026-04-24T20:39:44Z",
  "published" : "2026-04-14T23:15:00Z",
  "aliases" : [ "CVE-2026-40943" ],
  "summary" : "Oxia affected by server crash via race condition in session heartbeat handling",
  "details" : "### Summary\nA 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`).\n\n### Impact\nA 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.\n\nAll versions are affected.\n\n### Details\nIn `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.\n\nAdditionally, 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.\n\n### Patches\nFixed 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.\n\n### Workarounds\nNo workaround available.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/oxia-db/oxia"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.16.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.16.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/oxia-db/oxia/security/advisories/GHSA-5gqc-qhrj-9xw8"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40943"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/oxia-db/oxia"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-14T23:15:00Z",
    "nvd_published_at" : "2026-04-21T22:16:19Z"
  }
}