Vulnerabilities

Vulnerability · CVE-2026-39383

Gotenberg is an API-based document conversion tool.

Published May 5, 2026 · catalog updated Jul 24, 2026 · Gotenberg is an API-based

Check if you run it

No confirmed exploitation is on record for CVE-2026-39383. EPSS is 0.31%. Act only if a listed version of Gotenberg is an API-based is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Gotenberg is an API-based).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium6.9
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.31%
Remediation
Advisory link
Affected products
cpe thecodingmachine/gotenberg

Gotenberg is an API-based document conversion tool. In version 8.29.1, an unauthenticated attacker with network access can force the server to make outbound HTTP POST requests to arbitrary internal or external destinations by supplying a crafted URL in the Gotenberg-Webhook-Url request header. The FilterDeadline function in filter.go is intended to gate outbound URLs, but when both the allow-list and deny-list are empty (the default configuration), it returns nil unconditionally and permits any URL. This is a blind SSRF: Gotenberg POSTs the converted document to the webhook URL and only checks whether the response status code is an error, but never returns the target's response body to the attacker. An attacker can use this to probe internal network infrastructure by observing whether the error callback is invoked, force POST requests against internal services that perform side effects, and confirm reachability of cloud metadata endpoints. The retryable HTTP client issues up to 4 automatic retries per request, amplifying each probe. This issue has been fixed in version 8.31.0. As a workaround, configure the GOTENBERG_API_WEBHOOK_ALLOW_LIST environment variable to restrict webhook URLs to known receivers, or set GOTENBERG_API_WEBHOOK_DENY_LIST to block RFC-1918 and link-local address ranges.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

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  • cpe thecodingmachine/gotenbergversion unspecified

How to fix CVE-2026-39383

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-39383. EPSS is 0.31%. Act only if a listed version of Gotenberg is an API-based is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-918: Server-Side Request Forgery (SSRF). EPSS 0.31%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 5, 2026 · NIST NVD

    Detected

    Gotenberg is an API-based document conversion tool. In version 8.29.1, an unauthenticated attacker with network access can force the server to make outbound HTTP POST requests to arbitrary internal or external destinations by supplying a crafted URL in the Gotenberg-Webhook-Url request header. The FilterDeadline function in filter.go is intended to gate outbound URLs, but when both the allow-list

  2. Jul 24, 2026 · NIST NVD

    Updated

    Gotenberg is an API-based document conversion tool. In version 8.29.1, an unauthenticated attacker with network access can force the server to make outbound HTTP POST requests to arbitrary internal or external destinations by supplying a crafted URL in the Gotenberg-Webhook-Url request header. The FilterDeadline function in filter.go is intended to gate outbound URLs, but when both the allow-list

Sources

  • CVE.orgVulnerability recordCVE-2026-39383

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-39383

    30-day exploitation probability 0.3%

    first.org
  • NIST NVDVulnerability recordCVE-2026-39383

    Gotenberg is an API-based document conversion tool. In version 8.29.1, an unauthenticated attacker with network access can force the server to make outbound HTTP POST requests to arbitrary internal or external destinations by supplying a crafted URL in the Gotenberg-Webhook-Url r

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.