# CVE-2026-105686: Penpot: Repeated chunk index causes temporary-storage amplification

> An authenticated user can cause resource exhaustion by repeatedly uploading chunks with the same index, leading to temporary storage amplification.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/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:** 5 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-qvq5-c536-pmx8

## What is CVE-2026-105686?

CVE-2026-105686 is a medium-severity denial of service vulnerability in penpot, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Penpot is an open-source design and prototyping platform. Prior to 2.18.0, the chunked media upload RPC validates that a chunk index is in range but neither rejects an already stored index nor replaces its previous object. An authenticated user can repeatedly upload the same valid index, causing each successful request to allocate another temporary object and increasing stored bytes beyond the upload session's declared logical size. Assembly detects the inconsistent chunk count only after allocation. This issue is fixed in version 2.18.0.

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

## Which versions are affected by CVE-2026-105686?


## How do I fix CVE-2026-105686?

No fix has been published for CVE-2026-105686 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-105686 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105686 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-105686 and fix it if it is affected.

What it is: CVE-2026-105686 is a medium-severity denial of service vulnerability in penpot, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105686 exists.

Affected product: penpot. 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-2026-105686/ (Markdown: https://insights.sbomify.com/CVE-2026-105686/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-105686
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-105686
- OSV: https://osv.dev/vulnerability/CVE-2026-105686

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-105686/
Summaries are generated and may contain mistakes; the official description above is the record.