CVE-2015-8539

The KEYS subsystem in the Linux kernel before 4.4 allows local users to gain privileges or cause a denial of service (BUG) via crafted keyctl commands that negatively instantiate a key, related to security/keys/encrypted-keys/encrypted.c, security/keys/trusted.c, and security/keys/user_defined.c.

Published: 2016-02-07 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-8539 is rated Moderate Risk (43.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.43%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2015-8539

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.08% 0.43% +0.34%
2 2025-03-30 0.32% 0.08% -0.24%
3 2025-03-29 — 0.32% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-8539

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2015-8539

OS Trackers for CVE-2015-8539

vendor priority summary link
debian unimportant CVE-2015-8539 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-8539
redhat high — https://access.redhat.com/security/cve/CVE-2015-8539
suse high CVE-2015-8539 severity important: SUSE including 243 source package names (kernel-3.10.0-693.17.1.el7, kernel-abi-whitelists-3.10.0-693.17.1.el7, …), 662 product×package rows across 99 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (99 product lines)): Fixed 362, Known Not Affected 300. https://www.suse.com/security/cve/CVE-2015-8539/
ubuntu medium CVE-2015-8539 medium priority: Ubuntu including 24 source packages (linux, linux-aws, …), 120 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): DNE 62, not-affected 32, released 25, ignored 1. https://ubuntu.com/security/CVE-2015-8539

Affected software / configurations for CVE-2015-8539

Vendor Product Version Raw CPE
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:-:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
suse linux_enterprise_real_time_extension 12 cpe:2.3:o:suse:linux_enterprise_real_time_extension:12:sp1:*:*:*:*:*:*
linux linux_kernel < 4.4 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 4.4 cpe:2.3:o:linux:linux_kernel:4.4:rc1:*:*:*:*:*:*
linux linux_kernel 4.4 cpe:2.3:o:linux:linux_kernel:4.4:rc2:*:*:*:*:*:*

References for CVE-2015-8539

URL Tags
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=096fe9eaea40a17e125569f9e657e34cdb6d73bd Vendor Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00007.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00008.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00009.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00011.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00017.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00018.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00019.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00020.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00021.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00022.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00034.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00094.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00045.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00000.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00038.html Third Party Advisory
http://www.openwall.com/lists/oss-security/2015/12/09/1 Issue Tracking Mailing List Patch Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:0151 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:0152 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:0181 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1284450 Issue Tracking Third Party Advisory
https://github.com/torvalds/linux/commit/096fe9eaea40a17e125569f9e657e34cdb6d73bd Issue Tracking Patch Vendor Advisory
https://usn.ubuntu.com/3798-1/ Third Party Advisory
https://usn.ubuntu.com/3798-2/ Third Party Advisory
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