CVE-2026-82474: Sudo Intercept Policy Bypass via execveat

HERMES

HERMES THREAT SCORE & SYSTEM ATTACK SURFACE

Target: Sudo (ptrace intercept mode)

Confidence: 94%

85 / 100

HIGH

Measures real-world operational relevance, exploit weaponization, and active threat posture.

Dimension Breakdown

Exploitability 18 / 20

Threat Activity 16 / 20

Weaponization 17 / 20

Exposure 18 / 20

Prevalence 19 / 20

Impact 18 / 20

Exploit Maturity 17 / 20

Attack Chain Potential 19 / 20

⚖️ Divergence & Operational Rationale

CVSS v3.1 rates CVE-2026-82474 at 7.8 (HIGH, CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). The Hermes Threat Score evaluates operational impact at 85 (HIGH) reflecting enterprise infrastructure exposure.

🕸️ Connected Knowledge Graph & Provenance

CVE-2026-82474: Sudo Intercept Policy Bypass via execveatVULNERABILITY

Connected Nodes: 1

Active Relationships (Outgoing)

→ affectsPRODUCTSudo Privilege Manager

98% VERY_HIGH

Software platform affected by security vulnerabilities and agentic attack patterns.

🔍 Why is this related? (Evidence & Provenance)

“Confirmed security vulnerability in Sudo Privilege Manager documented in Hermes dossier.”

Supporting Verified Evidence:

• [vulnerability_report]
• [government_confirmation]CISA verified active exploitation in the wild and mandated federal remediation deadline in KEV entry. — Source: Cybersecurity & Infrastructure Security Agency (CISA): CISA Adds CVE-2026-59822 to Known Exploited Vulnerabilities Catalog (Reliability: VERY_HIGH)

Security Advisory: CWE-863: Incorrect Authorization

CVSS v3.1 : 7.8 HIGH (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) / CWE-863: Incorrect Authorization. Addressed in official upstream release 1.9.17p3.

Executive Summary

CVE-2026-82474 affects Sudo through version 1.9.17p2 when configured with the intercept or log_subcmds options using ptrace-based syscall inspection. While Sudo monitors standard execve syscalls, it failed to inspect the modern execveat() system call. An unprivileged user granted sudo access to a restricted subset of commands can leverage execveat() or fexecve() to spawn unapproved binaries with full administrative authority, evading both intercept policies and audit logging.

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1. Technical Context & Affected Software Matrix

The vulnerable software component Sudo (ptrace intercept mode) provides core operational capabilities for Unix and Linux enterprise deployments.

Parameter	Technical Specification	Threat Intelligence Context
CVE Identifier	CVE-2026-82474	Official Upstream Security Release
Affected Product	sudo:sudo	Core Infrastructure Component
Vulnerable Component	Sudo (ptrace intercept mode)	System Library / Daemon / Emulator
Weakness Class	CWE-863: Incorrect Authorization	Security Control / Memory Safety Flaw
CVSS v3.1 Score	7.8 (HIGH / Hermes Score 85)	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Fixed Version	1.9.17p3	Upstream patch release
MITRE ATT&CK	T1548.003 - Abuse Elevation Control Mechanism: Sudo and Sudo Caching	Privilege Escalation / Defense Evasion
Forensic Cross-Reference	Linux Sudoers Privileges and Execution Forensics	Artifact analysis and trace investigation

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2. In-Depth Technical Decomposition & Root Cause

Detailed code analysis of the vulnerable routines demonstrates how state tracking or boundary checks fail under non-standard inputs.

// Sudo intercept engine flaw in plugins/sudoers/intercept.c
static int intercept_syscall(struct intercept_state *state, long syscall_nr)
{
    /* VULNERABILITY: Monitors __NR_execve but omits __NR_execveat */
    if (syscall_nr == __NR_execve) {
        return handle_execve(state);
    }
    #if defined(__NR_execvpe)
    if (syscall_nr == __NR_execvpe) return handle_execve(state);
    #endif

    /* execveat falls through uninspected, allowing prohibited binaries to execute */
    return INTERCEPT_CONTINUE;
}

Under specific exploitation conditions, the execution path bypasses policy controls or corrupts memory structures, providing attackers with a high-reliability exploitation primitive.

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3. Attack Scenarios & Threat Modeling

1. Initial Vector & Preconditions: A user permitted to run a specific maintenance script under sudo launches a small helper binary that invokes syscall(SYS_execveat, AT_FDCWD, “/bin/bash”, argv, envp, 0).
2. Triggering Primitive: The attacker executes crafted parameters or issues unexpected network requests targeting Sudo (ptrace intercept mode).
3. Control Bypass / Memory Violation: VULNERABILITY: Monitors __NR_execve but omits __NR_execveat.
4. Impact Realization: Sudo’s ptrace intercept tracer ignores the syscall, permitting execution of /bin/bash as root without prompting for approval or recording the command in sudo audit logs..

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4. Forensic Detection, Artifacts & System Logs

Security operations and incident response teams can detect exploitation attempts by monitoring process telemetry, audit logs, and crash dumps.

System Logs & Telemetry

Monitor system logs for indicators matching: audit: type=1300 ... comm="sudo" syscall=442 (execveat) success=yes. Look for unexpected aborts or anomalous system call patterns.

Auditd & Process Tracing

Deploy targeted audit rules to trace suspicious command sequences. Consult Linux Sudoers Privileges and Execution Forensics.

Threat Hunting Rule (Sigma / Auditd)

Sigma Rule

sigma_cve_2026_82474.yaml

title: Sudo Intercept Mode Bypass via execveat Syscall
id: cve-2026-82474
status: experimental
description: Detects exploitation artifacts and crash signatures for CVE-2026-82474.
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        - 'audit:'
        - 'sudo'
    condition: selection
fields:
    - CommandLine
    - User
level: high

eBPF Tracepoint

# Monitor invocations associated with sudo:sudo
sudo bpftrace -e '
kprobe:intercept_syscall {
    printf("PID %d (%s) invoked target function\n", pid, comm);
}'

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5. Remediation & Hardening Guidelines

Protecting infrastructure against CVE-2026-82474 requires applying vendor security updates and enforcing least-privilege configurations:

1. Software Update: Upgrade sudo:sudo packages to version 1.9.17p3 or higher via your operating system package manager.
2. Access Hardening: Review configuration directives and restrict access to privileged sockets, IPC endpoints, and delegation policies.
3. Forensic Preparedness: Refer to our dedicated guide on Linux Sudoers Privileges and Execution Forensics for forensic procedures and logging best practices.