What is CVE-2016-9806?

CVE-2016-9806 is a high-severity vulnerability in Linux Kernel, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.8/10. Published 2016-12-28.

How severe is CVE-2016-9806?

High severity. CVSS v3 base score is 7.8 out of 10.

Is CVE-2016-9806 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Double Free in Linux Kernel

CVE-2016-9806

Race condition in the netlink_dump function in net/netlink/af_netlink.c in the Linux kernel before 4.6.3 allows local users to cause a denial of service (double free) or possibly have unspecified other impact via a crafted application that makes sendmsg system calls, leading to a free operation associated with a new dump that started earlier than anticipated.

Vulnerability class: Race Condition

Published 2016-12-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (27.9th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Linux Kernel

Weakness classification (CWE)

Public proof-of-concept exploits

References

www.securityfocus.com/bid/94653 (VDB Entry, Third Party Advisory, vdb-entry)
www.securitytracker.com/id/1037968 (VDB Entry, Third Party Advisory, vdb-entry)
www.openwall.com/lists/oss-security/2016/12/03/4 (mailing-list, Patch, Mailing List, Third Party Advisory)
access.redhat.com/errata/RHSA-2017:2669 (vendor-advisory, Third Party Advisory)
github.com/torvalds/linux/commit/92964c79b357efd980812c4de5c1fd2ec8bb5520 (Patch, Third Party Advisory)
lists.openwall.net/netdev/2016/05/15/69 (mailing-list, Mailing List, Third Party Advisory)
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/ (Patch, Vendor Advisory)
access.redhat.com/errata/RHSA-2017:2077 (vendor-advisory, Third Party Advisory)
access.redhat.com/errata/RHSA-2017:1842 (vendor-advisory, Third Party Advisory)
source.android.com/security/bulletin/2017-03-01.html (Third Party Advisory)

Frequently asked questions

What is CVE-2016-9806?: CVE-2016-9806 is a high-severity vulnerability in Linux Kernel, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.8/10. Published 2016-12-28.
How severe is CVE-2016-9806?: High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2016-9806 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.