# CVE-2026-42886: Audiobookshelf: Memory amplification DoS via oversized compressed details entry in backup upload

> An admin user can crash the Audiobookshelf server by uploading a crafted ZIP file that causes memory exhaustion during decompression.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 May 2026
- **Updated:** 12 May 2026
- **Also known as:** GHSA-4jq4-rvq8-j26h

## What is CVE-2026-42886?

CVE-2026-42886 is a medium-severity denial of service vulnerability in advplyr audiobookshelf, published on 11 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Audiobookshelf is a self-hosted audiobook and podcast server. Prior to 2.32.2, the POST /api/backups/upload endpoint decompresses the details entry from an uploaded .audiobookshelf ZIP file entirely into memory using zip.entryData(), with no limit on the decompressed size. The upload middleware also has no file size limit. An admin user can upload a crafted ZIP containing a highly compressed details entry that, when decompressed, consumes hundreds of megabytes or gigabytes of memory, crashing the server process via out-of-memory. This vulnerability is fixed in 2.32.2.

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

## Which versions are affected by CVE-2026-42886?


## How do I fix CVE-2026-42886?

No fix has been published for CVE-2026-42886 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-42886 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42886 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42886 and fix it if it is affected.

What it is: CVE-2026-42886 is a medium-severity denial of service vulnerability in advplyr audiobookshelf, published on 11 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42886 exists.

Affected product: advplyr audiobookshelf. 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-2026-42886/ (Markdown: https://insights.sbomify.com/CVE-2026-42886/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42886
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42886
- OSV: https://osv.dev/vulnerability/CVE-2026-42886

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42886/
Summaries are generated and may contain mistakes; the official description above is the record.