CVE-2015-3246 Red Hat Libuser: software flaw
In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.
Confirmed exploited by CISA on · US federal patch deadline Sep 9, 2026
What to do
- Install Red Hat's security update for Libuser. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- Red Hat Libuser Race Condition Vulnerability
- Product
- Red Hat Libuser
- CISA description
- Red Hat libuser contains a race condition vulnerability that allows authenticated local users to corrupt the /etc/passwd file to cause a denial of service or privilege escalation.
- Type of flaw
- Software flaw
- Confirmed exploited
- Aug 26, 2026
- US federal patch deadline
- Sep 9, 2026
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Answering about CVE-2015-3246 ·
Questions about CVE-2015-3246
Is CVE-2015-3246 being exploited?
Yes. CISA added CVE-2015-3246 to its Known Exploited Vulnerabilities catalog on Aug 26, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2015-3246?
Install Red Hat's security update for Libuser. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2015-3246?
Only if you use Red Hat Libuser. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.