AUGUST 4, 2026
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Case File

CVE-2021-3156

HIGH · CVSS 7.8 EPSS 99.30% CISA KEV · Actively Exploited Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-01-26 · Last synced 2026-08-04

CyberRota Analysis

This is a high severity vulnerability with a CVSS score of 7.8. It is listed in CISA's Known Exploited Vulnerabilities catalog, indicating confirmed active exploitation in the wild. Public exploit code or proof-of-concept references have been detected in its references. Its EPSS score suggests a 99.3% probability of exploitation in the next 30 days.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CISA KEV Details

Status: This CVE is listed in CISA's Known Exploited Vulnerabilities catalog.

Ransomware use: Unknown

Added to KEV: 2022-04-06

Required action: Apply updates per vendor instructions.

CVE
CVE-2021-3156
Severity
HIGH
CVSS
7.8
EPSS
99.30%

Original NVD Description

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.

Related CVEs

Other vulnerabilities affecting the same vendor(s)