CVE-2021-3156: listed in the CISA KEV catalog

CVE-2021-3156 · CVSS 7.8 HIGH · EPSS 100.0% · KEV 2022-04-06

Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer overflow, which allows privilege escalation to root via "sudoedit -s" and a command-line argument that ends with a single backslash character.

Is CVE-2021-3156 exploited?

• Listed in the CISA KEV catalog on 2022-04-06.
• Federal remediation due 2022-04-27.
• Past that date by 1630 days.
• EPSS puts exploitation in the next 30 days at 100.0%.
• Public exploit code: packaged in a public tool.

Which products and versions are affected?

No affected package list recorded here yet.

Is there a patch?

No patch identifier recorded here yet.

What PlainSec published about CVE-2021-3156

• Google Cloud Split Its Patch Duty in Two (2026-08-26)
• UAT-10147 Turns Public Exploits Into Repeatable Ops (2026-08-21)
• Node Kernel Bugs on GKE COS Nodes Enable Host Escalation (2026-04-15)
• Google Cloud Issues Multiple Linux Kernel Privilege Escalation Fixes for GKE Nodes (2026-04-07)
• Multiple Linux Kernel Flaws Elevate Privileges on GCP Container Nodes (2026-04-03)
• Multiple High-Severity Cloud Vulnerabilities Impact Container Nodes (2026-04-01)

Primary sources

• NVD record
• CISA KEV catalog
• Metasploit: exploit/linux/local/sudo_baron_samedit
• Exploit-DB 49522
• Exploit-DB 49521

What this record does not say

• No affected package data.
• No patch identifier.

KEV and EPSS are re-checked daily. Record last updated 2026-09-24.