# CVE-2026-35458: Gotenberg has a ReDoS via extraHttpHeaders scope feature

> Attackers can cause indefinite worker hangs in Gotenberg by supplying malicious regex patterns, leading to denial of service.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Apr 2026
- **Updated:** 9 Apr 2026
- **Also known as:** GHSA-fmwg-qcqh-m992, GO-2026-5372

## What is CVE-2026-35458?

CVE-2026-35458 is a high-severity denial of service vulnerability in gotenberg, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Gotenberg is an API for converting document formats. In 8.29.1 and earlier, Gotenberg uses dlclark/regexp2 to compile user-supplied scope patterns without setting a proper timeout. Users with access to features using this logic can hang workers indefinitely.

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-35458?

4 open source packages ship an affected version, including github.com/gotenberg/gotenberg/v8 and github.com/gotenberg/gotenberg/v7. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/gotenberg/gotenberg/v8` | Go | All versions | 8.30.0 |
| `github.com/gotenberg/gotenberg/v8` | Go | All versions | 8.30.0 |
| `github.com/gotenberg/gotenberg/v8` | Go | All versions | 8.30.0 |
| `github.com/gotenberg/gotenberg/v7` | Go | All versions | None |

Products: Thecodingmachine Gotenberg.

## How do I fix CVE-2026-35458?

Upgrade github.com/gotenberg/gotenberg/v8 to 8.30.0 or later.

## Is CVE-2026-35458 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35458 exists.

## Other vulnerabilities in gotenberg

- [CVE-2026-40281](https://insights.sbomify.com/CVE-2026-40281/): Gotenberg vulnerable to argument injection via newlines in ExifTool metadata values (critical 10.0)
- [CVE-2026-42589](https://insights.sbomify.com/CVE-2026-42589/): Gotenberg: Unauthenticated RCE via ExifTool Metadata Key Injection (critical 9.8)
- [CVE-2020-13450](https://insights.sbomify.com/CVE-2020-13450/): Path traversal in n/a (critical 9.8)
- [CVE-2020-13451](https://insights.sbomify.com/CVE-2020-13451/): Code injection in n/a (critical 9.8)
- [CVE-2020-13452](https://insights.sbomify.com/CVE-2020-13452/): Privilege escalation in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-35458 and fix it if it is affected.

What it is: CVE-2026-35458 is a high-severity denial of service vulnerability in gotenberg, published on 7 Apr 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-2026-35458 exists.

Affected packages and fixed versions:
- github.com/gotenberg/gotenberg/v8 (Go): affected all versions; fixed in 8.30.0
- github.com/gotenberg/gotenberg/v8 (Go): affected all versions; fixed in 8.30.0
- github.com/gotenberg/gotenberg/v8 (Go): affected all versions; fixed in 8.30.0
- 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-2026-35458/ (Markdown: https://insights.sbomify.com/CVE-2026-35458/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35458
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35458
- OSV: https://osv.dev/vulnerability/CVE-2026-35458

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-35458/
Summaries are generated and may contain mistakes; the official description above is the record.