# CVE-2026-45742: Gotenberg: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

> An unauthenticated remote attacker can crash the Gotenberg PDF conversion service by triggering a race condition in concurrent file processing.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Aug 2026
- **Updated:** 19 Aug 2026
- **Also known as:** GHSA-vp73-vjw8-8f32, GO-2026-5669

## What is CVE-2026-45742?

CVE-2026-45742 is a high-severity vulnerability in gotenberg, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Gotenberg is a Docker-powered stateless API for PDF files. From 8.10.0 until 8.33.0, the newContext function in pkg/modules/api/context.go starts one errgroup.Go goroutine for each multipart downloadFrom entry and allows those goroutines to concurrently write to the shared ctx.files, ctx.diskToOriginal, and ctx.filesByField maps and slices. Go maps and slices are not safe for concurrent mutation, so a crafted multipart request containing many downloadFrom entries can trigger a data race and terminate the process with a fatal concurrent map writes runtime error. The default configuration enables downloadFrom and disables authentication, allowing an unauthenticated remote attacker to crash an exposed conversion service and cause a denial of service. This issue is fixed in version 8.33.0.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-45742?

4 open source packages ship an affected version, including github.com/gotenberg/gotenberg/v8 and github.com/gotenberg/gotenberg/v7.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/gotenberg/gotenberg/v8` | Go | From 8.10.0 | 8.33.0 |
| `github.com/gotenberg/gotenberg/v8` | Go | From 8.10.0 | 8.33.0 |
| `github.com/gotenberg/gotenberg/v8` | Go | From 8.10.0 | 8.33.0 |
| `github.com/gotenberg/gotenberg/v7` | Go | All versions | None |

## How do I fix CVE-2026-45742?

Upgrade github.com/gotenberg/gotenberg/v8 to 8.33.0 or later.

## Is CVE-2026-45742 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-45742 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45742 and fix it if it is affected.

What it is: CVE-2026-45742 is a high-severity vulnerability in gotenberg, published on 19 Aug 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-2026-45742 exists.

Affected packages and fixed versions:
- github.com/gotenberg/gotenberg/v8 (Go): affected from 8.10.0; fixed in 8.33.0
- github.com/gotenberg/gotenberg/v8 (Go): affected from 8.10.0; fixed in 8.33.0
- github.com/gotenberg/gotenberg/v8 (Go): affected from 8.10.0; fixed in 8.33.0
- github.com/gotenberg/gotenberg/v7 (Go): affected all versions; no fix listed

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-2026-45742/ (Markdown: https://insights.sbomify.com/CVE-2026-45742/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45742
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45742
- OSV: https://osv.dev/vulnerability/CVE-2026-45742

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45742/
Summaries are generated and may contain mistakes; the official description above is the record.