CVE-2026-18086

Local code execution via improper JSSE bounds checks

Published Aug 13, 2026 · Updated Aug 13, 2026

Out-of-bounds write in JSSE on IBM operating-system releases 7.3 through 7.6 allows local users to execute arbitrary code or interrupt service. IBM has not disclosed the affected JSSE routine, attacker-controlled input, or incorrect bounds operation beyond identifying improper bounds checking. Exploitation requires low local privileges, no user interaction, and high attack complexity; the form of service interruption is unspecified.

CVSS severity4.5
Medium
EPSS probability0.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds write in JSSE on IBM operating-system releases 7.3 through 7.6 allows local users to execute arbitrary code or interrupt service. IBM has not disclosed the affected JSSE routine, attacker-controlled input, or incorrect bounds operation beyond identifying improper bounds checking. Exploitation requires low local privileges, no user interaction, and high attack complexity; the form of service interruption is unspecified.

The record

CVE
CVE-2026-18086
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
IBM
Product
IBM i
Classifications
CWE-787
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.3
  2. Affected versionversion=7.4
  3. Affected versionversion=7.5
  4. Affected versionversion=7.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

IBM · IBM iversion=7.3; version=7.4; version=7.5; version=7.6

Published CVSS scores

4.5IBMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
5.3NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo