CVE-2026-26933: Github.com/elastic/beats/v7 Packetbeat Does Not Properly Validate Vulnerability

MODERATE
Advisory Identifier: GHSA-27qj-9gvp-8rh9
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CVSS 5.7
CWE-129
Published
Advisory Summary

CVE-2026-26933 is a MODERATE (CVSS 5.7) packetbeat does not properly validate vulnerability (CWE-129: Improper Validation of Array Index) affecting Github.com/elastic/beats/v7 libraries in the Go ecosystem. The issue involves packetbeat does not properly validate an array index in multiple protocol parser components. Remediation is available by upgrading affected packages to version 7.0.0-alpha2.0.20260126223743-dec1b31111ec.

CVE-2026-26933 at a Glance

CVE Identifier CVE-2026-26933
GHSA Identifier GHSA-27qj-9gvp-8rh9
Severity MODERATE
CVSS v3.1 Base Score 5.7
CWE Classification CWE-129: Improper Validation of Array Index
Affected Product Github.com/elastic/beats/v7
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 5.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Adjacent (AV:A)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-26933

To remediate this vulnerability, upgrade all affected Github.com/elastic/beats/v7 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/elastic/beats/v7 fixed: 7.0.0-alpha2.0.20260126223743-dec1b31111ec 
Upgrade github.com/elastic/beats/v7 to 7.0.0-alpha2.0.20260126223743-dec1b31111ec
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/elastic/beats/v7

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-26933, inspect your project dependencies for Github.com/elastic/beats/v7:

inspect dependencies for github.com/elastic/beats/v7

Analyze the terminal output to locate any version of Github.com/elastic/beats/v7 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.0.0-alpha2.0.20260126223743-dec1b31111ec), 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-129: Improper Validation of Array Index, where the product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array. In Github.com/elastic/beats/v7, 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

Improper Validation of Array Index (CWE-129) in multiple protocol parser components in Packetbeat can lead Denial of Service via Input Data Manipulation (CAPEC-153). An attacker with the ability to send specially crafted, malformed network packets to a monitored network interface can trigger out-of-bounds read operations, resulting in application crashes or resource exhaustion. This requires the attacker to be positioned on the same network segment as the Packetbeat deployment or to control traffic routed to monitored interfaces.

CVE-2026-26933 Affected Github.com/elastic/beats/v7 Versions

1 component(s)
Fixed Versions:
7.0.0-alpha2.0.20260126223743-dec1b31111ec
Product / Package Ecosystem Affected Versions Fixed Version
github.com/elastic/beats/v7
golang/github.com/elastic/beats/v7
Go
< 7.0.0-alpha2.0.20260126223743-dec1b31111ec
7.0.0-alpha2.0.20260126223743-dec1b31111ec

References

NVD — CVE-2026-26933 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-26933
Security Fix Commit FIX COMMIT
https://github.com/elastic/beats/commit/941098459db6556b837194f40c076b08d51137cb
Security Fix Commit FIX COMMIT
https://github.com/elastic/beats/commit/dec1b31111ec3500b82db21ba67dde5c914ee94d
Github.com/elastic/beats/v7 Security Information SECURITY
https://discuss.elastic.co/t/packetbeat-8-19-11-9-2-5-security-update-esa-2026-11/385533
Github.com/elastic/beats/v7 Source Repository REPOSITORY
https://github.com/elastic/beats

Frequently Asked Questions

What is CVE-2026-26933?
CVE-2026-26933 is a security vulnerability in Github.com/elastic/beats/v7 involving Packetbeat does not properly validate an array index in multiple protocol parser components under CWE-129: Improper Validation of Array Index.
Which Github.com/elastic/beats/v7 versions are affected?
Affected versions include releases prior to 7.0.0-alpha2.0.20260126223743-dec1b31111ec across affected packages: github.com/elastic/beats/v7.
What version fixes CVE-2026-26933?
Upgrading to 7.0.0-alpha2.0.20260126223743-dec1b31111ec (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/elastic/beats/v7 affected?
Yes, github.com/elastic/beats/v7 is affected in releases prior to 7.0.0-alpha2.0.20260126223743-dec1b31111ec. Upgrade your dependency to 7.0.0-alpha2.0.20260126223743-dec1b31111ec or later.
What is the CVSS score of CVE-2026-26933?
CVE-2026-26933 has a CVSS v3.1 base score of 5.7 (MODERATE) with vector string CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-26933?
CVE-2026-26933 is classified under CWE-129: Improper Validation of Array Index (The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.).
How can I check Go dependencies for CVE-2026-26933?
Run the dependency tree command: 'inspect dependencies for github.com/elastic/beats/v7'. 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-27qj-9gvp-8rh9",
  "modified" : "2026-03-19T21:23:15Z",
  "published" : "2026-03-19T18:31:19Z",
  "aliases" : [ "CVE-2026-26933" ],
  "summary" : "Packetbeat does not properly validate an array index in multiple protocol parser components",
  "details" : "Improper Validation of Array Index (CWE-129) in multiple protocol parser components in Packetbeat can lead Denial of Service via Input Data Manipulation (CAPEC-153). An attacker with the ability to send specially crafted, malformed network packets to a monitored network interface can trigger out-of-bounds read operations, resulting in application crashes or resource exhaustion. This requires the attacker to be positioned on the same network segment as the Packetbeat deployment or to control traffic routed to monitored interfaces.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/elastic/beats/v7"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "7.0.0-alpha2.0.20260126223743-dec1b31111ec"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-26933"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/elastic/beats/commit/941098459db6556b837194f40c076b08d51137cb"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/elastic/beats/commit/dec1b31111ec3500b82db21ba67dde5c914ee94d"
  }, {
    "type" : "WEB",
    "url" : "https://discuss.elastic.co/t/packetbeat-8-19-11-9-2-5-security-update-esa-2026-11/385533"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/elastic/beats"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-129" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-19T21:23:15Z",
    "nvd_published_at" : "2026-03-19T18:16:21Z"
  }
}