# CVE-2026-80189: LeafWiki 0.10.0 through 0.12.0 Uncontrolled Resource Consumption via Unbounded ZIP Extraction

> An Editor can cause denial of service by uploading a highly compressed ZIP file that exhausts disk or memory resources during extraction.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Aug 2026
- **Updated:** 29 Aug 2026
- **Also known as:** GHSA-258m-crqp-25xc, GHSA-vx6x-47wx-xjjj

## What is CVE-2026-80189?

CVE-2026-80189 is a high-severity denial of service vulnerability in perber leafwiki, published on 25 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

LeafWiki extracts an uploaded ZIP archive without limiting how much data it will write. ZipExtractor.ExtractToDir in internal/importer/zip_extractor.go opens each entry and copies it to the destination with io.Copy, which runs to the end of the decompressed stream, so only the size of the uploaded archive is bounded and the size it expands to is not. The import route that reaches this code requires the Editor or Admin role, and the upload itself is capped at 500 MiB compressed. Because a ZIP entry can compress at a very high ratio, an archive well inside that cap can expand to hundreds of gigabytes as it is written out. The extraction directory defaults to a location under the operating system temporary directory, so the written data consumes the disk backing that path, which on a tmpfs-backed temporary directory is memory. A user holding the Editor role can therefore exhaust the storage the service depends on and keep it from serving, using far more resource than the upload limit alone would permit.

Weakness: CWE-409 (Improper Handling of Highly Compressed Data (Data Amplification))

## Which versions are affected by CVE-2026-80189?


## How do I fix CVE-2026-80189?

No fix has been published for CVE-2026-80189 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-80189 being exploited?

There is no known exploitation of CVE-2026-80189 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80189 and fix it if it is affected.

What it is: CVE-2026-80189 is a high-severity denial of service vulnerability in perber leafwiki, published on 25 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-80189 in the wild and no public exploit code.

Affected product: perber leafwiki. 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-2026-80189/ (Markdown: https://insights.sbomify.com/CVE-2026-80189/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80189
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80189
- OSV: https://osv.dev/vulnerability/CVE-2026-80189

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80189/
Summaries are generated and may contain mistakes; the official description above is the record.