CVE-2026-76239: stigmem-node has blind SSRF via unvalidated webhook subscription delivery_address

CVE-2026-76239 · Severity: medium · CVSS 6.3 · Published 2026-08-19

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.

Technologies: stigmem-node (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2026-76239 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-76239 being exploited in the wild.
How severe is CVE-2026-76239?
Medium severity, with a CVSS score of 6.3, published 19 August 2026.
Which products and versions are affected?
stigmem-node (PyPI) ECOSYSTEM:introduced=0,fixed=0.9.0a11.
Is there a fix for CVE-2026-76239?
Yes. stigmem-node (PyPI): upgrade to 0.9.0a11 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-76239?
Check whether you run stigmem-node (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • stigmem-node (PyPI): upgrade to 0.9.0a11 or later
    pip install "stigmem-node>=0.9.0a11"

Affected products

  • stigmem-node (PyPI) ECOSYSTEM:introduced=0,fixed=0.9.0a11

Identifiers

  • CVE-2026-76239
  • GHSA-5p3m-vhh6-9236

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