CVE-2026-76239 Stigmem before 0.9.0a11 SSRF via unvalidated webhook delivery_address
Authenticated users can trigger server-side requests to internal services via unvalidated webhook addresses, enabling blind SSRF attacks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-76239?
CVE-2026-76239 is a medium-severity server-side request forgery vulnerability in eidetic-labs stigmem-node, published on 19 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-918
Which versions are affected by CVE-2026-76239?
2 open source packages ship an affected version, including stigmem-node.
| Package | Affected | Fixed in |
|---|---|---|
stigmem-node PyPI | All versions | 0.9.0a11 |
stigmem-node PyPI | All versions | 0.9.0a11 |
How do I fix CVE-2026-76239?
Upgrade stigmem-node to 0.9.0a11 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-76239 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-76239 exists.
Sources
Also known as GHSA-5p3m-vhh6-9236, GHSA-xq22-gq5h-mvx5.