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Not in CISA KEV
HIGH severity

CVE-2026-42591 v8

HIGH

CVE-2026-42591 is a high-severity (CVSS 8.2) Server-Side Request Forgery (SSRF) vulnerability in github.com/gotenberg/gotenberg/v8. No vendor fix is recorded yet; mitigation options are listed below.

Gotenberg: Server-Side Request Forgery (SSRF) in github.com/gotenberg/gotenberg/v8

Also known asGHSA-rm4c-xj6x-49mwGO-2026-5627
Published
May 14, 2026
Updated
Aug 12, 2026
Affected
1 pkg
Patched
None yet
Exploits
None indexed
Exploitation data as of Sep 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-42591.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs17th percentile — riskier than 17% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2026-42591 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 376,715 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
🐹github.com/gotenberg/gotenberg/v8

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.32.0, the LibreOffice conversion endpoint (/forms/libreoffice/convert) passes uploaded documents directly to LibreOffice without inspecting their content. LibreOffice then fetches any embedded external URLs on its own, completely bypassing the SSRF filters. This vulnerability is fixed in 8.32.0.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/gotenberg/gotenberg/v8all versionsNo fix

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/gotenberg/gotenberg/v8, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    No patched version of github.com/gotenberg/gotenberg/v8 has shipped for CVE-2026-42591 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-42591 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-42591. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.32.0, the LibreOffice conversion endpoint (/forms/libreoffice/convert) passes uploaded documents directly to LibreOffice without inspecting their content. LibreOffice then fetches any embedded external URLs on its own, completely bypassing the SSRF filters. This vulnerability is fixed in 8.32.0.
O3 Security · Impact-Aware SCA

Is CVE-2026-42591 in your dependencies?

O3 Security finds CVE-2026-42591 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2026-42591: v8 SSRF (High 8.2) | O3 Security