CVE-2026-18077 IBM i is Affected By Multiple Vulnerabilities in Simple Mail Transfer Protocol

High 7.5 Published Updated

A remote attacker can cause a denial of service via a stack-based buffer overflow in the SMTP component of IBM i.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-18077?

CVE-2026-18077 is a high-severity memory corruption vulnerability in Ibm I, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to cause a denial of service due to a stack-based buffer overflow.

Weakness: CWE-787

Which versions are affected by CVE-2026-18077?

It affects 1 product.

Products include Ibm I.

How do I fix CVE-2026-18077?

No fix has been published for CVE-2026-18077 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-18077 being exploited?

There is no known exploitation of CVE-2026-18077 in the wild and no public exploit code.

All Ibm I vulnerabilities

Sources

Also known as GHSA-x7cj-5r2f-7fw3.

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