CVE-2026-90999

Sentry Seer vulnerability allows attacker-controlled input to be executed in a privileged environment

Published: Sep 16, 2026Updated: Sep 18, 2026 Sources: CVE List NVDCWE-20

9.8CRITICAL

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.

In plain language

AI Act now

Sentry Seer can let an outsider send fake data that runs harmful commands in a high-permission automation system, so businesses using it for privileged automated operations should act now.

Executive summary

Unauthenticated network-based arbitrary code execution arises when attacker-controlled Sentry telemetry is interpreted as instructions by Sentry Seer agents operating in a privileged environment.

If affected, business impact

Full automation-system takeoverSensitive data exposureUnauthorized system changesService disruptionRansomware risk

What to do now

Check whether your organization uses Sentry Seer for automated agent operations with high system permissions.
Temporarily stop or isolate any Sentry Seer agents that accept data from the internet and can run privileged commands.
No fixed version has been published; ask the vendor for a security update and deploy it as soon as one is available.

May need vendor / contractor work

What is it

Sentry Seer can mistake fake incoming data for a legitimate instruction and act on it with powerful system access. It is like an automated employee accepting a forged work order and being allowed to use the master keys.

Who is affected

This matters to you if you use Sentry Seer for automated agent operations that have elevated permissions. It is especially important where those agents can receive telemetry or event data from outside your organization. The issue is only relevant when Sentry Seer is used in a privileged automation environment.

How urgent is it

Urgent because an attacker can send crafted data over the network without needing an account, causing high-permission automation to run malicious commands. There is no confirmed public exploitation or public exploit code at present, but the impact of a successful attack is severe and no patch information is available.

What to do — in detail

Confirm whether Sentry Seer is deployed and identify every agent that processes external or untrusted telemetry while holding privileged operating-system, cloud, or automation permissions. Review whether those agents can execute commands or trigger workflows based on incoming event content.

No fixed version or supported upgrade path is currently available. Contact the vendor for an advisory, supported mitigation, and release timeline; do not rely on an unverified version number.

Until a fix is available, disable affected privileged agent operations where practical, or isolate them from internet-reachable telemetry sources. Restrict inbound access to trusted sources and remove unnecessary elevated permissions from the automation environment.

CISA has not added this CVE to the Known Exploited Vulnerabilities catalog, so no CISA remediation due date is provided. Monitor Sentry Seer agent logs for unexpected inbound events, unusual command execution, privilege changes, and outbound connections from automation hosts.

Technical context

CVE-2026-90999 is rated CVSS 9.8 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). It is an unauthenticated, network-reachable arbitrary-code-execution issue involving attacker-controlled telemetry crossing a trust boundary and being interpreted as executable agent instructions in a privileged environment; reported CWEs include CWE-20, CWE-74, CWE-94, CWE-116, and CWE-913. No public exploit code is recorded, and no clear dated reporting confirms exploitation in the wild. CISA KEV does not list this CVE. EPSS predicts 0.5% likelihood (42nd percentile) with a flat trend.

This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:HConfidentiality

High

I:HIntegrity

High

A:HAvailability

High

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Weaknesses

CWE-20 CWE-74 CWE-94 CWE-116 CWE-913

Affected Products

Functional Software, Inc.

Sentry Seer

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

Is your org exposed to CVE-2026-90999?Request an assessment to establish which checks are appropriate for your systems. Check my exposure

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques

Execution

Initial Access

View detailed technique mapping

References

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

kb.cert.org

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

kb.cert.org

News mentions

⚡ Weekly Recap: Cisco 0-Day, AI Agent RCE, ClickFix Attacks, ClickFix Surge, and Browser Hijacks
en·The Hacker News·Sep 21, 2026 Exploited Cisco Identity Services Engine zero-day

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