CVE-2026-90999: Input Validation Flaw (CVSS 9.8)

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.

Is your site exposed to CVE-2026-90999?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.8

CRITICAL

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

EPSS — Exploit Prediction

0.0067

Probability of exploitation

0.51%

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-20 Improper Input Validation

CWE-74 CWE-74

CWE-94 CWE-94

CWE-116 CWE-116

CWE-913 CWE-913

References

Other References

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

Frequently Asked Questions

What is CVE-2026-90999? +

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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-90999? +

CVE-2026-90999 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0067, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-90999? +

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.

Related Vulnerabilities

CVE-2025-13826

Zervit's portable HTTP/web server is vulnerable to remote DoS attacks when a configuration reset request is made. The vulnerability is …

CVE-2026-62658

A security flaw was discovered in certain NETGEAR Nighthawk RAX series routers that could allow someone already logged in to …

CVE-2024-54011

Penetration Testing engineers at Amazon have discovered a flaw where the camera system fails to properly handle data supplied in …

CVE-2026-54700

ConnectBot SSH Client Library is written in Kotlin with Kaitai Struct and KStateMachine. Prior to 0.3.1, the SSH protocol parser …

CVE-2026-56349

n8n before version 2.10.0 contains an input validation vulnerability in the Guardrail node that allows attackers to bypass default guardrail …

CVE-2026-6409

A Denial of Service (DoS) vulnerability exists in the Protobuf PHP library during the parsing of untrusted input. Maliciously structured …

CVE-2026-90999