PatchTheCVECVE-2026-76239: Stigmem before 0.9.0a11 fails to validate the delivery_address parameter when creating webhook subscriptions,
28
Routine
MEDIUM 6.3
CVE-2026-76239 is a medium-severity flaw (CVSS 6.3) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 6.3 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 76%) |
| CISA exploited list | No |
| Weakness | CWE-918 |
| Published | 2026-08-19 |
| Last modified | 2026-10-23 |
Publisher (CNA): VulnCheck
Timeline
- Published CVE record published
- Updated Record last modified
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Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.