CVE-2018-15687: systemd · Race Condition
Affects systemdSource CVE Database V5
Public exploit available (Exploit-DB) · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 1.0% chance of exploitation in 30 days – higher than 64% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 26 Oct 2018
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by Canonical Ltd.
, 65 days before disclosure
CVE published
on cve.org
, t = 0
First Exploit-DB entry (opens in a new tab)
systemd - 'chown_one()' Dereference Symlinks
, 3 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubsystemd/systemdpkg:github/systemd/systemdOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
To mitigate this vulnerability, organizations should: 1) Upgrade systemd to a patched version beyond 239 where the race condition is resolved. 2) Restrict local user access to trusted personnel only, minimizing the risk of local exploitation. 3) Employ mandatory access controls (e.g., SELinux, AppArmor) to limit the impact of unauthorized permission changes. 4) Monitor file permission changes on critical system files and directories using file integrity monitoring tools to detect suspicious activity. 5) Regularly audit and update Linux systems to ensure all components, including systemd, are current with security patches. 6) Harden user privilege management to reduce the number of users with local access and limit the use of sudo or similar privilege escalation mechanisms.
Description
A race condition in chown_one() of systemd allows an attacker to cause systemd to set arbitrary permissions on arbitrary files. Affected releases are systemd versions up to and including 239.