Cyber Resilience

CVE-2026-9155

HighRCE

Published: 25 June 2026

Published
25 June 2026
Modified
27 June 2026
KEV Added
—
Patch
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CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0092 55.8th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-9155 is a high-severity OS Command Injection (CWE-78) vulnerability in Gnu Sed. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Unix Shell (T1059.004); ranked in the top 44.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability details

OS Command Injection vulnerability in Rapid7 InsightConnect Sed Plugin on Linux allows authenticated attackers to execute arbitrary OS commands via the expression parameter due to insufficient input validation.

CWE(s)
CWE-78

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
Why these techniques?

CWE-78 OS command injection on Linux directly enables arbitrary Unix shell command execution (T1059.004).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

gnu
sed
4.2.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

References