Gotenberg Vulnerable to ReDoS via extraHttpHeaders scope feature

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

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 · score source

EPSS

• CVE-2026-35458: 0.50% estimated exploitation activity in the next 30 days; percentile 42.70 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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. Details Gotenberg uses dlclark/regexp2 to compile user-supplied scope patterns (gotenberg/pkg/modules/chromium/routes.go:200) with no MatchTimeout set, therefore using the default of math.MaxInt64 = "forever". For example, any user with access to the endpoint /forms/chromium/screenshot/url can add a crafted scope pattern to the extraHttpHeaders form field using a nested quantifiers that causes infinite backtracking, hanging the Gotenberg worker indefinitely. See the dlclark/regexp2 README.md for further considerations. Tested on the latest container version gotenberg/gotenberg:8.29.1 PoC The following Python script uses the /forms/chromium/screenshot/url endpoint, testing for differences in responses times between simple and malicious regexes. Impact This is a ReDoS vulnerability which only…

Published by the source

7 Apr 2026, 18:16 UTC

Last modified by the source

7 Apr 2026, 18:16 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-fmwg-qcqh-m992

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# Patch Next advisory brief: CVE-2026-35458

Advisory: Gotenberg Vulnerable to ReDoS via extraHttpHeaders scope feature
IDs: CVE-2026-35458, GHSA-fmwg-qcqh-m992
Record: https://patchnext.com/advisories/cve-2026-35458 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/gotenberg/gotenberg/v8 8.30.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gotenberg/gotenberg/v8: affected <= 8.29.1; fixed in 8.30.0

## Suggested inspection (read-only)
- Go github.com/gotenberg/gotenberg/v8: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/gotenberg/gotenberg/v8.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-fmwg-qcqh-m992 (GitHub-reviewed advisory GHSA-fmwg-qcqh-m992 lists affected ranges: Go github.com/gotenberg/gotenberg/v8 >=0 <=8.29.1)

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