CVE-2026-17491: IBM i 7.3, 7.4, 7.5, and 7.6 is could allow a remote authenticated attacker to bypass security restrictions du

Routine

MEDIUM 5.4DOWNGRADE

CVE-2026-17491 is a medium-severity flaw (CVSS 5.4) affecting i. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IBM i 7.3, 7.4, 7.5, and 7.6 is could allow a remote authenticated attacker to bypass security restrictions due to improper enforcement of the ChrootDirectory configuration directive.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 94%)
CISA exploited list	No
Weakness	CWE-269
Published	2026-10-16
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

2026-10-16 19:17 UTCPublished CVE record published
2026-10-23 15:40 UTCUpdated Record last modified

ibm i DOWNGRADE

Affected: 7.3 · 7.4 · 7.5 · 7.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.3

1. Check installed version

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

2. No fixed release: 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

2. No fixed release: 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.

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-2026-17491?

i: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-17491 being exploited?

CVE-2026-17491 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-2026-17491 affect?

CVE-2026-17491 affects i. Severity is medium (CVSS 5.4). IBM i 7.3, 7.4, 7.5, and 7.6 is could allow a remote authenticated attacker to bypass security restrictions due to improper enforcement of the ChrootDirectory configuration directive.

How urgent is CVE-2026-17491?

Priority 20/100. No elevated risk signals yet.

Related CVEs

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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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