CVE-2026-81858Network attack vector

Disclosure and service disruption via out-of-bounds read

Published Oct 12, 2026 · Updated Oct 12, 2026

An out-of-bounds read in IBM i File Server allows remote authenticated users to obtain information and disrupt service over the network. IBM identifies releases 7.3, 7.4, 7.5, and 7.6 as affected but does not disclose the faulty operation or triggering input. File Server authentication is required; the information exposed and whether disruption causes a hang or crash are unspecified.

CVSS severity5.4
Medium
EPSS probability0.48%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds read in IBM i File Server allows remote authenticated users to obtain information and disrupt service over the network. IBM identifies releases 7.3, 7.4, 7.5, and 7.6 as affected but does not disclose the faulty operation or triggering input. File Server authentication is required; the information exposed and whether disruption causes a hang or crash are unspecified.

The record

CVE
CVE-2026-81858
Published
Oct 12, 2026
Updated
Oct 12, 2026
Vendor
IBM
Product
IBM i
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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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 vectornetwork
Required privilegesauthenticated

What is affected?

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

Published CVSS scores

5.4IBMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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