CVE-2026-89088Public exploit

Application crash via unchecked FAT16 directory read

Published Oct 16, 2026 · Updated Oct 16, 2026

A heap overflow in Parted's FAT16 resize logic allows attackers to crash applications via a crafted file system image. The duplicate_legacy_root_dir function reads a metadata-controlled root directory sector count into a heap buffer without checking its capacity. A user or administrator must resize the malformed image; the documented consequence is an application crash, not a system reboot.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A heap overflow in Parted's FAT16 resize logic allows attackers to crash applications via a crafted file system image. The duplicate_legacy_root_dir function reads a metadata-controlled root directory sector count into a heap buffer without checking its capacity. A user or administrator must resize the malformed image; the documented consequence is an application crash, not a system reboot.

The record

CVE
CVE-2026-89088
Published
Oct 16, 2026
Updated
Oct 16, 2026
Vendor
libuser Project
Product
Red Hat Enterprise Linux 9
Classifications
CWE-787, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 16, 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?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

libuser Project · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.
libuser Project · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.
libuser Project · Red Hat Enterprise Linux 10Affected versions are unavailable in this record.
libuser Project · Red Hat Enterprise Linux 7Affected versions are unavailable in this record.

Published CVSS scores

7.1Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
5.5Red HatCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

Public exploit references

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

Technologies

Your stack

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Your stack

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