GotenbergApplication · Thecodingmachine

CVE-2026-35458

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-07
Fix available
A fix is available. Upgrade to 8.29.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Gotenberg versions 8.29.1 and earlier use the dlclark/regexp2 library to compile user-supplied scope patterns (regular expressions) without implementing a timeout mechanism. Attackers with access to affected features can supply malicious regex patterns that cause the regexp2 compilation to hang indefinitely, effectively denying service by hanging worker processes.

MitigationImplement a timeout context around all regexp2 compilation operations, or upgrade to a patched version once available, to prevent unbounded regex processing.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
GotenbergApplication
Affected:< 8.29.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Gotenberg version
    Query the Gotenberg health endpoint (e.g., curl http://<host>/health) or inspect the container image: docker inspect <container> | grep -i gotenberg
    Affected if Version returned or embedded is 8.29.1 or earlier (< 8.29.1)
  2. Identify if scope/regex patterns are accepted by API
    Review API documentation or capture live traffic to determine if any endpoint accepts a 'scope' parameter that gets compiled as a regex pattern
    Affected if The API accepts scope parameter values from users that are processed as regexp2 patterns
  3. Confirm authenticated users can submit patterns
    Check the authentication configuration and endpoint permissions to see if authenticated users can access the scope pattern functionality
    Affected if Authenticated users have access to API endpoints that process scope/regex patterns
  4. Check if regexp2 library is used without timeout
    Review application dependencies (go.mod, vendor folder, or binary analysis) for dlclark/regexp2 usage in scope pattern compilation code
    Affected if The codebase uses dlclark/regexp2 to compile user-supplied patterns without a timeout mechanism

You are affected if Gotenberg version is below 8.29.1 AND authenticated users can submit scope/regex patterns to the API that get compiled by the regexp2 library without timeout protection.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 8.29.1 or later
Fixed in 8.29.1
Interim mitigation

Implement a timeout context around all regexp2 compilation operations, or upgrade to a patched version once available, to prevent unbounded regex processing.

Recommended fix High confidence

8.29.1

  1. 1. Identify the current Gotenberg version running in your environment
  2. 2. Backup all Gotenberg configuration files and any persistent data
  3. 3. Upgrade Gotenberg to version 8.29.1 or later
  4. 4. Verify the upgrade by checking the new version number
  5. 5. Test that the API functionality remains operational
  6. 6. Monitor worker processes to confirm the timeout fix is effective
Caveat No breaking changes reported for this patch release; 8.29.1 is a security fix

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Gotenberg Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-35458 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-35458 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data