# CVE-2026-26933: Improper Validation of Array Index in Packetbeat Leading to Denial of Service

> An attacker on the same network segment can crash Packetbeat by sending malformed network packets that trigger out-of-bounds reads in protocol parsers.

- **Severity:** Medium 5.7 (`CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Mar 2026
- **Updated:** 19 Mar 2026
- **Also known as:** ECHO-2325-2fc0-293f, GHSA-27qj-9gvp-8rh9, GO-2026-4789, MINI-436j-j77x-w2j5, MINI-5m6m-f2j5-vf7p, MINI-97gv-cprr-p257, MINI-9hjx-pvqx-5q45, MINI-cjf2-rjpg-gqrr, MINI-fvmp-5xpr-r2pf, MINI-mjmx-3qmw-vpx7, MINI-vrvc-jhwh-m52m, MINI-wmcc-28j5-f67x, MINI-wrqx-9hw4-8j38

## What is CVE-2026-26933?

CVE-2026-26933 is a medium-severity denial of service vulnerability in Elastic Packetbeat, published on 19 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-129 (Improper Validation of Array Index)

## Which versions are affected by CVE-2026-26933?

4 open source packages ship an affected version, including github.com/elastic/beats/v7 and github.com/elastic/beats. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/elastic/beats/v7` | Go | All versions | 7.0.0-alpha2.0.20260126223743-dec1b31111ec |
| `github.com/elastic/beats/v7` | Go | All versions | 7.0.0-alpha2.0.20260126223743-dec1b31111ec |
| `github.com/elastic/beats/v7` | Go | All versions | 7.0.0-alpha2.0.20260126223743-dec1b31111ec |
| `github.com/elastic/beats` | Go | All versions | None |

Products: Elasticsearch Packetbeat.

## How do I fix CVE-2026-26933?

Upgrade github.com/elastic/beats/v7 to 7.0.0-alpha2.0.20260126223743-dec1b31111ec or later.

## Is CVE-2026-26933 being exploited?

There is no known exploitation of CVE-2026-26933 in the wild and no public exploit code.

## Other vulnerabilities in Elastic Packetbeat

- [CVE-2017-11480](https://insights.sbomify.com/CVE-2017-11480/): Denial of Service in Packetbeat (high 7.5)
- [CVE-2025-68381](https://insights.sbomify.com/CVE-2025-68381/): Packetbeat Improper Bounds Check (medium 6.5)
- [CVE-2025-68382](https://insights.sbomify.com/CVE-2025-68382/): Packetbeat Out-of-bounds Read (medium 6.5)
- [CVE-2026-26932](https://insights.sbomify.com/CVE-2026-26932/): Improper Validation of Array Index in Packetbeat Leading to Denial of Service (medium 5.7)
- [CVE-2025-68388](https://insights.sbomify.com/CVE-2025-68388/): Elasticsearch Packetbeat has Excessive Allocation of Memory and CPU via Malicious IPv4 Fragments (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-26933 and fix it if it is affected.

What it is: CVE-2026-26933 is a medium-severity denial of service vulnerability in Elastic Packetbeat, published on 19 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-26933 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/elastic/beats/v7 (Go): affected all versions; fixed in 7.0.0-alpha2.0.20260126223743-dec1b31111ec
- github.com/elastic/beats/v7 (Go): affected all versions; fixed in 7.0.0-alpha2.0.20260126223743-dec1b31111ec
- github.com/elastic/beats/v7 (Go): affected all versions; fixed in 7.0.0-alpha2.0.20260126223743-dec1b31111ec
- github.com/elastic/beats (Go): affected all versions; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-26933/ (Markdown: https://insights.sbomify.com/CVE-2026-26933/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-26933
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-26933
- OSV: https://osv.dev/vulnerability/CVE-2026-26933

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-26933/
Summaries are generated and may contain mistakes; the official description above is the record.