---
id: CVE-2026-76239
title: >-
  Stigmem before 0.9.0a11 fails to validate the delivery_address parameter when
  creating webhook subscriptions, allowing authenticated users to specify
  internal loopback and private network destinations
summary: >-
  Stigmem before 0.9.0a11 fails to validate the delivery_address parameter when
  creating webhook subscriptions, allowing authenticated users to specify
  internal loopback and private network destinations. Attackers can trigger
  matching fact…
severity: medium
cvss: 6.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L'
cwe:
  - CWE-918
vendor: stigmem-node
product: stigmem-node
affected:
  - stigmem-node < 0.9.0a11
patched:
  - stigmem-node 0.9.0a11
published: '2026-08-19'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:06:30.133'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76239'
references:
  - url: >-
      https://github.com/eidetic-labs/stigmem/security/advisories/GHSA-5p3m-vhh6-9236
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/stigmem-before-0a11-ssrf-via-unvalidated-webhook-delivery-address
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/eidetic-labs/stigmem/security/advisories/GHSA-5p3m-vhh6-9236
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/eidetic-labs/stigmem/pull/726'
  - url: >-
      https://github.com/eidetic-labs/stigmem/commit/11637401d50629fef040382aee5af4571842c152
  - url: >-
      https://github.com/eidetic-labs/stigmem/commit/2ff5be29291d1c042e00d57c5f9ef93650cc90e0
  - url: 'https://github.com/eidetic-labs/stigmem'
  - url: 'https://github.com/eidetic-labs/stigmem/releases/tag/v0.9.0a11'
tags:
  - nvd
  - osv
  - pip
epss: 0.00324
epssPercentile: 0.25298
aliases:
  - GHSA-5p3m-vhh6-9236
ecosystem: pip
ingestedAt: '2026-08-20T19:23:05.131Z'
---

## Overview

Stigmem before 0.9.0a11 fails to validate the delivery_address parameter when creating webhook subscriptions, allowing authenticated users to specify internal loopback and private network destinations. Attackers can trigger matching fact-change events to cause the Stigmem server to issue server-side HTTP POST requests to internal services, enabling blind SSRF attacks against localhost and private network endpoints.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-76239)

Affected packages:

- `stigmem-node < 0.9.0a11`

Patched in:

- `stigmem-node 0.9.0a11`

Source: https://osv.dev/vulnerability/GHSA-5p3m-vhh6-9236