CVE-2026-81421 ddfourtwo sentry-selfhosted-mcp raw_sentry_api server-side request forgery
Attackers can exploit a server-side request forgery vulnerability in the Sentry MCP server to access internal resources or bypass security controls.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-81421?
CVE-2026-81421 is a medium-severity server-side request forgery vulnerability in ddfourtwo sentry-selfhosted-mcp, published on 26 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A security flaw has been discovered in ddfourtwo sentry-selfhosted-mcp 0.4.0. The affected element is an unknown function of the component raw_sentry_api. The manipulation of the argument endpoint results in server-side request forgery. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
Weakness: CWE-918
Which versions are affected by CVE-2026-81421?
How do I fix CVE-2026-81421?
No fix has been published for CVE-2026-81421 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-81421 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81421 exists.
Sources
Also known as GHSA-77f3-qj56-x322.