What is CVE-2026-9155?

CVE-2026-9155 is a high-severity vulnerability in GNU Sed, classified under OS Command Injection. CVSS score: 8.8/10. Published 2026-06-25.

How severe is CVE-2026-9155?

High severity. CVSS v3 base score is 8.8 out of 10.

RCE in GNU Sed

CVE-2026-9155

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.

Vulnerability class: Command Injection (OS Command Injection)

Published 2026-06-25 · last modified 2026-06-27.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.016 (74.8th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

GNU Sed — versions 4.2.2
Linux Kernel
Rapid7 Insightconnect Sed Plugin — versions 0, 2.0.5

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

extensions.rapid7.com/extension/sed (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-9155?: CVE-2026-9155 is a high-severity vulnerability in GNU Sed, classified under OS Command Injection. CVSS score: 8.8/10. Published 2026-06-25.
How severe is CVE-2026-9155?: High severity. CVSS v3 base score is 8.8 out of 10.