Exploited· due 2026-09-095.1mediumMedium

CVE-2015-3246

Redhat Enterprise Linux

libuser before 0.56.13-8 and 0.60 before 0.60-7, as used in the userhelper program in the usermode package, directly modifies /etc/passwd, which allows local users to cause a denial of service (inconsistent file state) by causing an error during the modification. NOTE: this issue can be combined with CVE-2015-3245 to gain privileges.

Exploitation status

CISA has confirmed this is being exploited in the wild. That is an observation of real attacks, not a prediction.
US federal civilian agencies are required to remediate it by 2026-09-09. That deadline does not bind private companies, but it is a reasonable benchmark for how urgently CISA views it.
A vendor advisory or patch reference has been published.

Required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

CISA’s wording, unedited.

What the metrics mean

It is requires local access to the machine.
For an attacker who can reach it, exploitation depends on conditions outside the attacker's control.
To exploit it, no account is needed.
Beyond that, no action by a user is required.

Scoring

CVSS: 5.1 (v3.1)
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-264
Assigned by: secalert@redhat.com

Dates

Published: 2015-08-11
Last modified: 2026-08-27
Added to KEV: 2026-08-26
Remediation due: 2026-09-09
Sources: CISA KEV, NVD

Affected products

Redhat Enterprise Linux5.0, 6.0, 7.0
Opensuse Opensuse13.2
Libuser Project Libuser- 0.56.13-8, 0.60 - 0.60-7

As listed in the NVD configuration data. Not a statement about your estate.