CVE-2015-3246
Red Hat — Red Hat Libuser Race Condition Vulnerability
Red Hat · CWE-264 | CWE-367 · in CISA KEV since 2026-08-26
EVRS 75 of 100 Urgent
Patch This Cycle
Rank 1,044 of 2,960 tracked
Raised to the floor for a confirmed exploited vulnerability.
Why it scores 75
Evidence available: 6 of 7 signalsListed in the CISA KEV catalog, and an EPSS probability of 0.085.
- CISA KEVApplied
- RansomwareDid not apply
- Vendor exploitationDid not apply
- EPSSApplied
- Microsoft Exploitability IndexNot applicable
- Pre-patch disclosureNo data
- KEV recencyApplied
- CVSSApplied
The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data
Fix
Patch or fixed version identifiedCISA required action
- This vulnerability affects an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see
- BOD 26-04
- Forensics Triage Requirements
- nvd.nist.gov/…/CVE-2015-3246
Fixed in
libuser -> 1:0.56.9.dfsg.1-1.2ubuntu2+esm1 | libuser -> 1:0.62~dfsg-0.1
Affected versions
- libuser
< 0.56.13-8>= 0.60 < 0.60-7 - enterprise linux
5.06.07.0 - opensuse
13.2
Remediation
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.
Fixed versions from NVD.
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | 5.1 | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.085 (95th pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Confirmed | CISA KEV |
| Ransomware campaign useWhether CISA has seen ransomware operators use it. | Unknown or none | CISA KEV |
| CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. | 2026-09-09 · CISA federal deadline · Overdue by 43 days | CISA KEV |
| Public exploit moduleA module existing is not the same as active exploitation. | Public module exists | Metasploit |
| EUVD cross-referenceENISA's record: CVSS 7.4 (v3.1), assigned by redhat. | Listed | ENISA EUVD |
Description
NVDlibuser 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.
What CISA says to do
- This vulnerability affects an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see
- BOD 26-04
- Forensics Triage Requirements
- nvd.nist.gov/…/CVE-2015-3246
Public module
Metasploit lists a public great-rank module for this CVE: Libuser roothelper Privilege Escalation (linux/local/libuser_roothelper_priv_esc). A module existing is not the same as active exploitation; see metasploit.com.