CVE-2026-76239: SSRF (CVSS 6.3)

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.

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CVSS v3.1 Score

6.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

EPSS — Exploit Prediction

0.0027

Probability of exploitation

0.19%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-918 Server-Side Request Forgery (SSRF)

References

Other References

https://github.com/eidetic-labs/stigmem/security/advisories/GHSA-5p3m-vhh6-9236 https://www.vulncheck.com/advisories/stigmem-before-0a11-ssrf-via-unvalidated-webhook-delivery-address https://github.com/eidetic-labs/stigmem/security/advisories/GHSA-5p3m-vhh6-9236

Frequently Asked Questions

What is CVE-2026-76239? +

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. It has a CVSS v3.1 base score of 6.3 (MEDIUM).

How severe is CVE-2026-76239? +

CVE-2026-76239 has a CVSS v3.1 score of 6.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0027, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-76239? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-76239