CVE-2015-3246
Red Hat Libuser Race Condition Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 9 September 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 3.1
- 7.4 HIGHCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 8.50% probability · 95th percentile
- Public exploits
- 2 in Exploit-DB · verified · first 27 July 2015
- CISA KEV
- Listed 26 August 2026 · due 9 September 2026
- Weakness
- CWE-264, CWE-367
- Affected
- redhat/enterprise linux · opensuse/opensuse · libuser project/libuser
- Source
- secalert@redhat.com
EPSS 8.5% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
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. 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: https://access.redhat.com/articles/1537873 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2015-3246
Public exploits (2)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- http://lists.fedoraproject.org/pipermail/package-announce/2015-August/163044.htmlBroken Link
- http://lists.fedoraproject.org/pipermail/package-announce/2015-July/162947.htmlBroken Link
- http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00000.htmlMailing List, Third Party Advisory
- http://rhn.redhat.com/errata/RHSA-2015-1482.htmlVendor Advisory
- http://rhn.redhat.com/errata/RHSA-2015-1483.htmlVendor Advisory
- http://www.securityfocus.com/bid/76022Third Party Advisory
- http://www.securitytracker.com/id/1033040Third Party Advisory
- https://access.redhat.com/articles/1537873Mitigation, Vendor Advisory
- https://www.exploit-db.com/exploits/44633/Third Party Advisory, VDB Entry
- https://www.qualys.com/2015/07/23/cve-2015-3245-cve-2015-3246/cve-2015-3245-cve-2015-3246.txtExploit
- http://lists.fedoraproject.org/pipermail/package-announce/2015-August/163044.htmlBroken Link
- http://lists.fedoraproject.org/pipermail/package-announce/2015-July/162947.htmlBroken Link
- http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00000.htmlMailing List, Third Party Advisory
- http://rhn.redhat.com/errata/RHSA-2015-1482.htmlVendor Advisory
- http://rhn.redhat.com/errata/RHSA-2015-1483.htmlVendor Advisory
- http://www.securityfocus.com/bid/76022Third Party Advisory
- http://www.securitytracker.com/id/1033040Third Party Advisory
- https://access.redhat.com/articles/1537873Mitigation, Vendor Advisory
- https://www.exploit-db.com/exploits/44633/Third Party Advisory, VDB Entry
- https://www.qualys.com/2015/07/23/cve-2015-3245-cve-2015-3246/cve-2015-3245-cve-2015-3246.txtExploit
- https://blog.talosintelligence.com/uat-10147-chinese-speaking-adversary-integrates-agentic-ai-into-post-compromise-operations/Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2015-3246US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.