# CVE-2026-45742: Gotenberg race condition in multipart downloadFrom handling

Source: https://junglewise.ai/threats/cve-2026-45742-gotenberg-race-condition-in-multipart-downloadfrom-handling  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-19. Updated: 2026-05-29  
License: CC BY 4.0 with a link back

CVE-2026-45742 · Severity: high · CVSS 7.5 · Published 2026-08-19

Gotenberg, a tool used for converting various document formats into PDFs, is vulnerable to a denial-of-service attack. An attacker can send a specially crafted request that causes the service to crash by triggering a race condition during file processing. This results in the service becoming unavailable to users, potentially disrupting automated document workflows.

Technologies: [github.com/gotenberg/gotenberg/v7 (Go)](https://junglewise.ai/threats/technologies/github-com-gotenberg-gotenberg-v7), [github.com/gotenberg/gotenberg/v8 (Go)](https://junglewise.ai/threats/technologies/github-com-gotenberg-gotenberg-v8), [Gotenberg](https://junglewise.ai/threats/technologies/gotenberg). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Gotenberg](https://junglewise.ai/threats/vendors/gotenberg).

## Quick answers

**Is CVE-2026-45742 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45742 being exploited in the wild.

**How severe is CVE-2026-45742?** High severity, with a CVSS score of 7.5, published 19 August 2026.

**Which products and versions are affected?** github.com/gotenberg/gotenberg/v7 (Go) SEMVER:introduced=0; github.com/gotenberg/gotenberg/v8 (Go) >= 8.10.0, <= 8.32.0, SEMVER:introduced=8.10.0,fixed=8.33.0; Gotenberg >= 8.10.0, <= 8.32.0.

**Is there a fix for CVE-2026-45742?** Yes. github.com/gotenberg/gotenberg/v8 (Go): upgrade to 8.33.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-45742 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-45742?** Check whether you run github.com/gotenberg/gotenberg/v7 (Go), github.com/gotenberg/gotenberg/v8 (Go) or Gotenberg at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/gotenberg/gotenberg/v8 (Go): upgrade to 8.33.0 or later

  ```sh
  go get github.com/gotenberg/gotenberg/v8@v8.33.0
  ```


## Technical details

A race condition exists in Gotenberg's `pkg/modules/api/context.go` within the `newContext` function. When processing multipart requests containing multiple `downloadFrom` entries, the application spawns concurrent goroutines to download files. These goroutines attempt to write to shared request context maps (`ctx.files`, `ctx.diskToOriginal`, and `ctx.filesByField`) without proper synchronization. Because Go maps are not thread-safe for concurrent writes, a crafted request can trigger a runtime panic (`fatal error: concurrent map writes`), leading to process termination. This can be exploited by an unauthenticated remote attacker if the default configuration (authentication disabled) is used. The issue is resolved in version 8.33.0.

## Affected products

- Gotenberg Gotenberg >= 8.10.0, <= 8.32.0

## Identifiers

- CVE-2026-45742
- GHSA-vp73-vjw8-8f32
- GO-2026-5669

## Timeline

- 2026-05-29: disclosed
- 2026-05-29: advisory
- 2026-05-29: patched: Fixed in version 8.33.0

## References

- [https://api.github.com/users/uokik](https://api.github.com/users/uokik)
- [https://github.com/uokik](https://github.com/uokik)
- [https://api.github.com/users/uokik/gists%7B/gist_id%7D](https://api.github.com/users/uokik/gists%7B/gist_id%7D)
- [https://api.github.com/users/uokik/repos](https://api.github.com/users/uokik/repos)
- [https://avatars.githubusercontent.com/u/112353771?v=4](https://avatars.githubusercontent.com/u/112353771?v=4)
- [https://api.github.com/users/uokik/events%7B/privacy%7D](https://api.github.com/users/uokik/events%7B/privacy%7D)

## Related threats

- [Gotenberg server-side request forgery in IsPublicIP IPv6 handling](https://junglewise.ai/threats/cve-2026-126799-gotenberg-8-31-0-before-8-38-0-contains-a-server-side-request)
- [Gotenberg SSRF deny-list bypass in IsPublicIP via IPv6 prefixes](https://junglewise.ai/threats/cve-2026-45741-gotenberg-ssrf-deny-list-bypass-in-ispublicip-via-ipv6-prefixes)
- [Gotenberg path traversal via Windows-style separators in ZIP entry names](https://junglewise.ai/threats/cve-2026-44829-gotenberg-path-traversal-via-windows-style-separators-in-zip)
- [Gotenberg SSRF and local file disclosure in LibreOffice conversion](https://junglewise.ai/threats/cve-2026-55229-gotenberg-ssrf-and-local-file-disclosure-in-libreoffice)
- [GO-2026-5587 - Gotenberg has incomplete fix for ExifTool arbitrary file write: case-insensitive bypass and missing…](https://junglewise.ai/threats/go-2026-5587-gotenberg-has-incomplete-fix-for-exiftool-arbitrary-file-5b46f3f0)