# CVE-2026-103042: LightLLM through 1.2.0 Unauthenticated Memory Exhaustion via NCCL Control Channel set_value

> Unauthenticated attackers can exhaust memory in LightLLM via NCCL control channel, causing worker crashes and node failure.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Sep 2026
- **Updated:** 2 Oct 2026
- **Also known as:** GHSA-mqxw-j6vh-r94f

## What is CVE-2026-103042?

CVE-2026-103042 is a high-severity denial of service vulnerability in ModelTC LightLLM, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

LightLLM through 1.2.0 contains a memory exhaustion vulnerability in the NCCL control channel when started with --pd_trans_mode nccl, allowing unauthenticated attackers to exhaust KV-transfer worker memory. Attackers can call the exposed_set_value method to store unbounded key-value pairs without size limits, causing the worker process to crash and triggering node failure.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-103042?


## How do I fix CVE-2026-103042?

No fix has been published for CVE-2026-103042 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103042 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103042 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103042 and fix it if it is affected.

What it is: CVE-2026-103042 is a high-severity denial of service vulnerability in ModelTC LightLLM, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103042 exists.

Affected product: ModelTC LightLLM. 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-2026-103042/ (Markdown: https://insights.sbomify.com/CVE-2026-103042/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103042
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103042
- OSV: https://osv.dev/vulnerability/CVE-2026-103042

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103042/
Summaries are generated and may contain mistakes; the official description above is the record.