# CVE-2026-11946: GetEndpoints Memory Exhaustion in open62541

> Unauthenticated attackers can exhaust server memory in open62541 by sending oversized GetEndpoints requests, causing denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Jul 2026
- **Updated:** 2 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-11946, GHSA-qwmm-q68h-5qf6, UBUNTU-CVE-2026-11946

## What is CVE-2026-11946?

CVE-2026-11946 is a high-severity denial of service vulnerability in open62541, published on 2 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An unauthenticated remote attacker can exhaust
server memory via the GetEndpoints Discovery Service in open62541. The
endpointUrl field of GetEndpointsRequest is not validated for length. An
attacker can declare an arbitrarily large string (up to ~4.09 GB via the UInt32
length field) delivered across intermediate chunks without ever sending the
final chunk. The server buffers all chunks in RAM indefinitely until the
SecureChannel times out. The attack is
pre-session and bypasses all encryption configurations.

The issue affects open62541: from 1.4.0 through 1.4.16, from 1.5.0 through 1.5.4, master.

Weakness: CWE-789 (Memory Allocation with Excessive Size Value), CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-11946?


## How do I fix CVE-2026-11946?

No fix has been published for CVE-2026-11946 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-11946 being exploited?

There is no known exploitation of CVE-2026-11946 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11946 and fix it if it is affected.

What it is: CVE-2026-11946 is a high-severity denial of service vulnerability in open62541, published on 2 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-11946 in the wild and no public exploit code.

Affected product: open62541. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-11946/ (Markdown: https://insights.sbomify.com/CVE-2026-11946/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11946
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11946
- OSV: https://osv.dev/vulnerability/CVE-2026-11946

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11946/
Summaries are generated and may contain mistakes; the official description above is the record.