What is the CVSS score of CVE-2026-18235?

CVE-2026-18235 has a CVSS 3.1 base score of 8.3 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L. EPSS exploitation probability: 0.3%.

Which versions of IBM i are affected by CVE-2026-18235?

IBM i systems running versions 7.3 through 7.6 are vulnerable to remote command execution by authenticated users with minimal privileges, threatening confidentiality and integrity of…. A patch is available.

How to fix or mitigate CVE-2026-18235?

Within 24 hours, inventory all IBM i systems to identify instances running versions 7.3 through 7.6 and prioritize those hosting business-critical applications. Within 7 days, obtain the vendor-released patches from IBM support, conduct compatibility testing in a non-production environment, and establish a deployment timeline; verify patch versions match your identified system releases. Within 30 days, deploy patches to all vulnerable production and non-production IBM i systems, with testing and validation prior to returning systems to normal operations.

IBM i CVE-2026-18235

EUVD-2026-57363 HIGH

OS Command Injection (CWE-78)

2026-08-12 ibm

GHSA-p8wh-xxx2-52hm

Command Injection IBM

8.3

CVSS 3.1 · Vendor: ibm

Severity by source

Vendor (ibm) PRIMARY

8.3 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L

vuln.today AI

8.3 HIGH

Network-reachable interface, low privilege credential required, no user interaction, high C/I from arbitrary CL execution, low A as system stability is not directly impacted.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L

4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N

Primary rating from Vendor (ibm).

CVSS VectorVendor: ibm

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

Low

Lifecycle Timeline

Analysis Generated

Aug 12, 2026 - 18:07 vuln.today

CVE Published

Aug 12, 2026 - 17:21 cve.org

HIGH 8.3

DescriptionCVE.org

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to execute arbitrary Control Language commands due to insufficient input validation.

AnalysisAI

IBM i versions 7.3 through 7.6 expose arbitrary Control Language (CL) command execution to remote authenticated attackers through insufficient input validation in a network-accessible interface. Any low-privileged IBM i user account is sufficient to exploit this flaw, enabling high-impact compromise of confidentiality and integrity on the affected system. No public exploit code or active exploitation has been identified at time of analysis, but the low attack complexity and broad version range across currently supported IBM i releases make this a meaningful patching priority for affected enterprises.

Technical ContextAI

IBM i (formerly OS/400 and i5/OS) is IBM's integrated operating system for Power Systems midrange hardware, widely used in banking, insurance, manufacturing, and government verticals. Its native scripting language, Control Language (CL), provides deep access to system objects, job management, database operations, and user administration - making arbitrary CL execution effectively equivalent to OS-level command injection on this platform. The root cause is CWE-78 (Improper Neutralization of Special Elements used in an OS Command), where user-supplied input is passed into a CL command processor without adequate sanitization or allowlisting. The affected CPE cpe:2.3:a:ibm:i:*:*:*:*:*:*:*:* with a wildcard version field indicates all patch levels of IBM i 7.3, 7.4, 7.5, and 7.6 are affected until the vendor-supplied fix is applied.

RemediationAI

Apply the vendor-supplied patch documented in IBM support advisory https://www.ibm.com/support/pages/node/7283292, which identifies the applicable PTFs for IBM i 7.3, 7.4, 7.5, and 7.6. An exact fix version string was not independently available in the source data - consult the advisory directly for the correct PTF numbers per release. As a compensating control while patching is scheduled, administrators should audit and restrict low-privilege user profiles that have access to the vulnerable interface, enforce the principle of least authority using IBM i's object-level authority model, and review CL command auditing via the Security Audit Journal (QAUDJRN) to detect anomalous command submissions. Restricting network access to IBM i management interfaces (e.g., TELNET, DDM, or relevant ports) to trusted subnets only reduces the network attack surface without impacting core application workloads.