How severe is CVE-2026-18509?

CVE-2026-18509 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-18509 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-18509?

CVE-2026-18509 primarily affects Ibm I. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-18509?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-18509 published?

CVE-2026-18509 was published on 2026-08-13 and last updated on 2026-08-17.

CVE-2026-18509

CVE-2026-18509 is a high-severity vulnerability in Ibm I with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-285.

Key facts

Severity: High (CVSS 3.x base score 8.2)
EPSS exploit prediction: 0% (6th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-285
Affected product: Ibm I
Published: 2026-08-13
Last modified: 2026-08-17

Description

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a local authenticated attacker to gain privilege escalation via the Navigator for i debugger. This could allow the attacker to access or manipulate sensitive data on the system, or create new profiles with elevated privileges on the IBM i system.

Frequently asked questions

What is CVE-2026-18509?: IBM i 7.6, 7.5, 7.4, and 7.3 could allow a local authenticated attacker to gain privilege escalation via the Navigator for i debugger. This could allow the attacker to access or manipulate sensitive data on the system, or create new profiles with elevated privileges on the IBM i system.
How severe is CVE-2026-18509?: CVE-2026-18509 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-18509 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-18509?: CVE-2026-18509 primarily affects Ibm I. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-18509?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-18509 published?: CVE-2026-18509 was published on 2026-08-13 and last updated on 2026-08-17.

References

https://www.ibm.com/support/pages/node/7283279

Affected products (4)

cpe:2.3:a:ibm:i:7.3:*:*:*:*:*:*:*
cpe:2.3:a:ibm:i:7.4:*:*:*:*:*:*:*
cpe:2.3:a:ibm:i:7.5:*:*:*:*:*:*:*
cpe:2.3:a:ibm:i:7.6:*:*:*:*:*:*:*

More vulnerabilities in Ibm I

CVE-2026-16860 — Critical (CVSS 9.9): IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to execute arbitrary code due to an…
CVE-2026-17083 — Critical (CVSS 9.8): IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to execute arbitrary code due to a stack-based buffer…
CVE-2026-17218 — Critical (CVSS 9.8): IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to execute arbitrary code due to an out-of-bounds write.
CVE-2026-17276 — Critical (CVSS 9.6): IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to escalate privileges due to improper…
CVE-2026-18193 — High (CVSS 8.9): IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to bypass security restrictions due to improper validation…
CVE-2026-18099 — High (CVSS 8.9): IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to execute arbitrary script code due to…

All CVEs affecting Ibm I →

Other CWE-285 (Improper Authorization) vulnerabilities

CVE-2025-65041 — Critical (CVSS 10.0): Improper authorization in Microsoft Partner Center allows an unauthorized attacker to elevate privileges over a network.
CVE-2023-33189 — Critical (CVSS 10.0): Pomerium is an identity and context-aware access proxy. With specially crafted requests, incorrect authorization…
CVE-2022-2595 — Critical (CVSS 10.0): Improper Authorization in GitHub repository kromitgmbh/titra prior to 0.79.1.
CVE-2021-28799 — Critical (CVSS 10.0): An improper authorization vulnerability has been reported to affect QNAP NAS running HBS 3 (Hybrid Backup Sync. ) If…
CVE-2026-55166 — Critical (CVSS 9.9): Lemur manages TLS certificate creation. Prior to 1.9.2, authenticated users could influence an ACME authority acme_url…
CVE-2026-34048 — Critical (CVSS 9.9): Coolify is an open-source and self-hostable tool for managing servers, applications, and databases. Prior to…

Browse all CWE-285 (Improper Authorization) vulnerabilities →