CVE-2015-8539

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2016-02-08 · updated 2026-06-17
Weakness: CWE-269

Description

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.

Affected products

Canonical Ubuntu Linux: 12.04, 14.04
Linux kernel: before 4.4; 4.4-rc1, 4.4-rc2 — fixed in 4.4
SUSE Linux Enterprise Real Time Extension: 12-sp1

How to fix

Upgrade to a fixed version: Linux kernel 4.4. Check the vendor advisory for mitigations.

References

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=096fe9eaea40a17e125569f9e657e34cdb6d73bd
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00007.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00008.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00009.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00011.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00017.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00018.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00019.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00020.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00021.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00022.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00034.html

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