Actively exploited · Published Aug 11, 2015 · Assigned by redhat

CVE-2015-3246

High 7.4 Exploited

In plain English

A high-severity security flaw in Libuser from Red Hat. Attackers are actively exploiting it in the wild (listed by CISA on August 26, 2026). The chance it is exploited in the next 30 days is estimated at 8.5% (higher than 95% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit, public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.4High
Exploit odds (30 days)8.5%top 4.9% of all CVEs
Exploited in the wildYesCISA KEV since Aug 26, 2026
Attack tooling2Metasploit, Public PoC

CISA guidance

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.

Federal agencies must remediate by Sep 9, 2026.

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12libuser1:0.62~dfsg-0.1DEBIAN-CVE-2015-3246
Debian:13libuser1:0.62~dfsg-0.1DEBIAN-CVE-2015-3246
Debian:14libuser1:0.62~dfsg-0.1DEBIAN-CVE-2015-3246
Ubuntu:25.10libuserno fix listedUBUNTU-CVE-2015-3246

Affected products (as reported)

VendorProductVersions
n/a n/a n/a

Weakness: CWE-367 · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References