CVE-2026-9636

HIGH
MEDIUM Priority: 0.02 BB Relevance: 66/100
Published: 2026-07-14 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network No Auth No Interaction Conf. Impact

CVSS Vector Breakdown

AV: Network
AC: High
PR: None
UI: None
S: X
AT: Present
VC: High
VI: None
VA: None

Description

A security issue exists within CompactLogix® 5380, ControlLogix® 5580, and EN4 communication modules related to CIP Security certificate revocation handling. The security issue stems from the controller failing to properly reject certificates signed by an intermediate certificate that has been revoked via a Certificate Revocation List (CRL). This could allow a network-based attacker to establish a connection using a certificate that should be untrusted, potentially bypassing CIP Security protections.

Weakness Classification (1)

Bug Bounty Relevance

66 / 100
✓ Network accessible
✓ No authentication
✓ No user interaction

CVSS Score

8.2 / 10.0 v4.0
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.22%
Raw Score 0.002160
Percentile 12.1%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00216
2026-10-28
0.00216

Intelligence Sources

nvd ref →