CVE-2026-18235: IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to execute arbitrary Control Language

This month

HIGH 8.3UPGRADE

CVE-2026-18235 is a high-severity flaw (CVSS 8.3) affecting i. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.3 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 55%)
CISA exploited list	No
Weakness	CWE-78
Published	2026-08-12
Last modified	2026-10-23

Publisher (CNA): IBM Corporation · Vendor: ibm

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-12 18:17 UTCPublished CVE record published
2026-10-23 19:10 UTCUpdated Record last modified

ibm i UPGRADE

Affected: >= 7.3 and <= 7.6

Fixed in: newer than 7.6

Safe to downgrade to: a release before 7.3

1. Check installed version

apt-cache policy i || rpm -q i || i --version

2. UPGRADE to newer than 7.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade i

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade i

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 7.3 (Debian / Ubuntu)

apt-cache madison i sudo apt install i=<VERSION_BEFORE_7.3> sudo apt-mark hold i

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list i sudo dnf downgrade i-<VERSION_BEFORE_7.3> sudo dnf versionlock add i

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora 46 · clementine · FIXED · 1.4.2-1.fc46 · FEDORA-2026-3e748ef4d3 · source

sudo dnf upgrade --advisory=FEDORA-2026-3e748ef4d3

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-18235?

i: upgrade to newer than 7.6. Exact commands for each OS are on this page.

Is CVE-2026-18235 being exploited?

CVE-2026-18235 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-18235 affect?

CVE-2026-18235 affects i. Severity is high (CVSS 8.3). 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.

How urgent is CVE-2026-18235?

Priority 40/100. High severity

Related CVEs

CVE-2026-18683 HIGH 8.8 MITIGATE IBM i 7.6, 7.5, 7.4, and 7.3 is vulnerable to privilege escalation via Navigator for i
CVE-2026-17095 HIGH 8.3 MITIGATE IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to bypass security restrictions due t
CVE-2026-18847 HIGH 8.8 MITIGATE IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote unauthenticated attacker to harvest credentials due to spoof
CVE-2026-18098 HIGH 8.1 MITIGATE IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to obtain sensitive information and c
CVE-2026-16694 MEDIUM 6.4 MITIGATE IBM i 7.6, 7.5, 7.4, and 7.3 is vulnerable to stored cross-site scripting

References

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