CVE-2026-39383
📛 CVE Title
Gotenberg unauthenticated blind SSRF via unfiltered webhook URL
Description
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.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- GitHub_M
- CVSS severity
- MEDIUM
- CVSS score
- 6.9 / 10
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N- Effective score
- 6.9 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-918 - Reserved
- 2026-04-07
- Published
- 2026-05-05 22:39 UTC
- Last updated
- 2026-05-06 17:32 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/39xxx/CVE-2026-39383.json
- Linked Threat
- CVE-2026-39383 — CVE-2026-39383
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-05 21:16:22 UTC
- NVD last modified
- 2026-05-08 19:02:10 UTC
- NVD CVSS v3.1
- 7.2 / 10 HIGH source: nvd@nist.gov
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 2.7 / 10
- EPSS score
- 0.0007 (probability of exploitation in next 30 days)
- EPSS percentile
- 20.75% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 12:03 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-27494 - Assigner
- GitHub_M
- Published
- May 5, 2026, 8:39:03 PM
- Updated
- May 6, 2026, 3:32:21 PM
- EUVD base score (CVSS 4.0)
-
6.9 / 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N - EUVD-reported EPSS
- 0.0700
- Vendors
- gotenberg
- Products
-
gotenberg (< 8.31.0)
- Aliases
-
GHSA-5vh4-rgv7-p9g4
ENISA description: 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.
EUVD references (1)
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| gotenberg | gotenberg |
< 8.31.0 (affected)
|
— |
Affected products — CPE 2.3 (1) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:a:thecodingmachine:gotenberg:*:*:*:*:*:*:*:*
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
- https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5vh4-rgv7-p9g4 x_refsource_CONFIRM
MITRE references (1) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
- https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5vh4-rgv7-p9g4 x_refsource_CONFIRM
Web references (3)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://nvd.nist.gov/vuln/detail/CVE-2026-39383 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-39383 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (2)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5vh4-rgv7-p9g4 security-advisories@github.com ExploitMitigationVendor Advisory
- https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5vh4-rgv7-p9g4 134c704f-9b21-4f2e-91b3-4a467353bcc0 ExploitMitigationVendor Advisory
Remediations (17)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:app.opencve.io
Remediation No vendor fix or workaround currently provided. OpenCVE Recommended Actions Upgrade Gotenberg to 8.31.0 or later to fix the SSRF issue. Configure the GOTENBERG_API_WEBHOOK_ALLOW_LIST environment variable to permit only trusted webhook URLs.
2026-05-23 21:13 UTC -
web:blog.talosintelligence.com
Microsoft has released its monthly security update for May 2026 , which includes 137 vulnerabilities affecting a range of products, including 16 that Microsoft marked as "critical".
2026-05-23 21:13 UTC -
web:cybersecuritynews.com
Microsoft released an out-of-band hotpatch update on March 13, 2026 , addressing serious security vulnerabilities in Windows 11 versions 24H2 and 25H2.
2026-05-23 21:13 UTC -
web:securereading.com
Microsoft has released its May 2026 Patch Tuesday security updates addressing multiple critical vulnerabilities affecting enterprise cloud services, operating systems, virtualization infrastructure, authentication platforms, and business applications.
2026-05-23 21:13 UTC -
web:support.microsoft.com
This out-of-band update for Windows 11, version 25H2 and 24H2 (KB5085518) includes fixes and improvements. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of Windows software updates ...
2026-05-23 21:13 UTC -
web:www.cisecurity.org
<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...
2026-05-23 21:13 UTC -
web:www.dbtsupport.com
The May 2026 Microsoft Patch Tuesday release includes security updates across supported Microsoft products and should be reviewed directly in the Microsoft Security Update Guide for the final CVE list, affected products, severity ratings, exploitability assessments, and any revised guidance.
2026-05-23 21:13 UTC -
web:www.forbes.com
Microsoft update breaks Windows — emergency fix suddenly released and available now.
2026-05-23 21:13 UTC -
web:www.windowslatest.com
Windows 11 April 2026 update adds Narrator Copilot support, faster Settings, File Explorer fixes, and key security improvements.
2026-05-23 21:13 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-05-23 21:13 UTC -
web:4sysops.com
Starting in April 2026 , Windows updates will change the default Kerberos ticket issuance behavior to AES-SHA1 for accounts without explicit encryption settings, while RC4 can still be used where explicitly enabled. This change, driven by CVE - 2026 -20833, affects every Windows Server environment where service accounts or devices still rely on RC4. Any service account, NAS device, or legacy ...
2026-05-26 02:46 UTC -
web:community.ui.com
Published: May 21, 2026 Updated: May 22, 2026 Version: 1.1 Revision: 1.1 Summary 1 of 5 A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection. Affected Products: UniFi OS Server (Version 5.0.6 and earlier) Mitigation : Update your UniFi OS Server to Version 5.0.8 or later ...
2026-05-26 02:46 UTC -
web:cve.akaoma.com
The exploitability of CVE-2026-39383 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs). Exploitability Analysis for CVE-2026-39383 With low attack complexity and no required privileges, CVE-2026-39383 is an easy target for cybercriminals.
2026-05-26 02:46 UTC -
web:msrc.microsoft.com
The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.
2026-05-26 02:46 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-26 02:46 UTC -
web:www.crowdstrike.com
Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.
2026-05-26 02:46 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-26 02:46 UTC
AI Forensic Analysis
Only Available for Registered Users. Sign in to view.
Raw JSON
The full cvelistV5 record. Download as CVE-2026-39383.json.
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-39383",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-05-06T15:32:04.175079Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-05-06T15:32:21.539Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5vh4-rgv7-p9g4"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "gotenberg",
"vendor": "gotenberg",
"versions": [
{
"status": "affected",
"version": "< 8.31.0"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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. \n\nThis 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.\n\nThis 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."
}
],
"metrics": [
{
"cvssV4_0": {
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 6.9,
"baseSeverity": "MEDIUM",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "LOW",
"subIntegrityImpact": "LOW",
"userInteraction": "NONE",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-918",
"description": "CWE-918: Server-Side Request Forgery (SSRF)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-05-05T20:39:03.651Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5vh4-rgv7-p9g4",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5vh4-rgv7-p9g4"
}
],
"source": {
"advisory": "GHSA-5vh4-rgv7-p9g4",
"discovery": "UNKNOWN"
},
"title": "Gotenberg unauthenticated blind SSRF via unfiltered webhook URL"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-39383",
"datePublished": "2026-05-05T20:39:03.651Z",
"dateReserved": "2026-04-06T22:06:40.515Z",
"dateUpdated": "2026-05-06T15:32:21.539Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}