---
id: "CVE-2026-115731"
kind: "vulnerability"
aliases: ["CVE-2026-115731"]
title: "Puppet Server: crafted report lets an agent certificate run code on the server"
severity: "critical"
cvss: 9.4
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "puppet-core", "fixed": ["9.1.3"], "affected": "unknown (vendor gives no range)", "ecosystem": "vendor"}]
ecosystems: []
tags: ["infrastructure", "puppet", "puppet-server", "self-hosted"]
not_affected_if: ["autosign-disabled"]
published_at: "2026-11-03T21:17:01+00:00"
first_seen_at: "2026-11-03T21:19:07+00:00"
updated_at: "2026-11-03T21:22:02+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115731", "first_seen_at": "2026-11-03T21:19:07+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-11-03T21:22:02+00:00"}]
---

# Puppet Server: crafted report lets an agent certificate run code on the server

Puppet Server deserializes untrusted data in its report-processing code, so a crafted rich-data type in a report submitted by PUT request can run arbitrary code. Any client holding a CA-signed agent certificate can exploit it, and an unauthenticated attacker can get such a certificate where the CA autosigns without strong verification.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:puppet-core affected unknown (vendor gives no range) fixed 9.1.3

## How to check

- Check the installed Puppet / Puppet Core version on the Puppet Server host (e.g. 'puppet --version', 'puppetserver --version') against 9.1.3; Puppet has not published an affected range (unknown), so treat earlier Puppet Core releases as possibly exposed.
- Check whether the CA autosigns agent certificate requests (the 'autosign' setting in puppet.conf, or an autosign.conf file); autosigning without strong verification lets an unauthenticated attacker obtain an agent certificate.
- Also check if you run Puppet Enterprise or a standalone Puppet Server: the vendor page read does not say which release fixes it there.

## Fix

Update to Puppet Core 9.1.3 (release notes list CVE-2026-115731 as fixed, PA-9473). The notes do not say which Puppet Server version carries the fix; the Puppet Server release notes (latest 9.0.17) do not mention it.

## Timeline

- 2026-11-03T21:19:07+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-115731
- 2026-11-03T21:22:02+00:00 analyst — Vendor release notes for Puppet Core 9.1.3 confirm the fix (PA-9473) but give no affected range, no Puppet Server/PE fixed version, no exploit details. NVD page returned nothing via web-cli. Need Puppet's security advisory for ranges.

## Documents

- [fix] Puppet Core 9.1.3 release notes https://help.puppet.com/core/current/content/puppetcore/PuppetReleaseNotes/release_notes_puppet_x-9-1-3.htm

## From the sources

Deserialization of untrusted data in the report-processing code of Puppet, as used by Puppet Server, in the affected releases, allows a client that holds any CA-signed agent certificate to execute arbitrary code on the Puppet Server as its service user by submitting a report containing a crafted rich-data type via PUT request. Where the certificate authority autosigns requests without strong verification, an unauthenticated network attacker can obtain such a certificate.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_