# CVE-2026-81334: darknet through 6.0 Out-of-Bounds Read and Write via Unchecked Layer Index in .cfg Parser

> Attackers can trigger out-of-bounds read and write via crafted configuration files, potentially leading to code execution or crashes.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 27 Aug 2026
- **Updated:** 27 Aug 2026
- **Also known as:** GHSA-727p-q944-q4q7

## What is CVE-2026-81334?

CVE-2026-81334 is a medium-severity memory corruption vulnerability in hank-ai darknet, published on 27 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

darknet subscripts its layer array with an index taken from a configuration file without checking it against the array's length. The array is allocated in src-lib/darknet_network.cpp as xcalloc(net.n, sizeof(Darknet::Layer)), sized to exactly the number of layer sections the file declares. The shortcut, scale_channels and sam sections supply that index through their from field and the route section through its layers field, and parse_shortcut_section in src-lib/darknet_cfg.cpp reads net.layers[index].outputs with no bounds check, which reads past the allocation. The dispatch loop in create_network then reuses the same index to assign net.layers[l.index].use_bin_output and net.layers[l.index].keep_delta_gpu, writing past the allocation at an offset the file controls, with a fixed one-byte value. Parsing a crafted configuration file is sufficient: the parse runs before any weights file is opened and needs no non-default option, so the result is a reliable crash and a write whose location, though not its value, is chosen by whoever supplied the file.

Weakness: CWE-787 (Out-of-bounds Write), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-81334?


## How do I fix CVE-2026-81334?

No fix has been published for CVE-2026-81334 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-81334 being exploited?

There is no known exploitation of CVE-2026-81334 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-81334 and fix it if it is affected.

What it is: CVE-2026-81334 is a medium-severity memory corruption vulnerability in hank-ai darknet, published on 27 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-81334 in the wild and no public exploit code.

Affected product: hank-ai darknet. 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-2026-81334/ (Markdown: https://insights.sbomify.com/CVE-2026-81334/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-81334
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-81334
- OSV: https://osv.dev/vulnerability/CVE-2026-81334

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-81334/
Summaries are generated and may contain mistakes; the official description above is the record.