CVE-2018-15686: systemd · Deserialization of Untrusted Data
Affects systemdSource CVE Database V5
Public exploit available (Exploit-DB) · CVSS 7.0 High.
Data as of 26 Oct 2026, 12:54 UTC
- EPSS
- 2.2% chance of exploitation in 30 days – higher than 82% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.0/AV:L/AC:H/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 - 'reexec' State Injection
, 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, European organizations should: 1) Immediately identify and inventory all Linux systems running systemd versions up to and including 239. 2) Apply available patches or upgrade systemd to a version later than 239 where the vulnerability is fixed. 3) Restrict local access to critical systems to trusted users only, minimizing the risk of local exploitation. 4) Implement strict access controls and monitoring to detect unusual systemd behavior or privilege escalation attempts. 5) Employ security tools that can detect deserialization anomalies or suspicious systemd re-executions. 6) Conduct regular security audits and penetration tests focusing on privilege escalation vectors. 7) Educate system administrators about the risks of untrusted input handling in system services and the importance of timely patching. These steps go beyond generic advice by emphasizing inventory, vendor coordination, access restriction, and behavioral monitoring specific to systemd and deserialization vulnerabilities.
Description
A vulnerability in unit_deserialize of systemd allows an attacker to supply arbitrary state across systemd re-execution via NotifyAccess. This can be used to improperly influence systemd execution and possibly lead to root privilege escalation. Affected releases are systemd versions up to and including 239.
References
- security.gentoo.org/glsa/201810-10 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2018/11/msg00017.html (opens in a new tab)
- securityfocus.com/bid/105747 (opens in a new tab)
- exploit-db.com/exploits/45714/ (opens in a new tab)
- usn.ubuntu.com/3816-1/ (opens in a new tab)
- access.redhat.com/errata/RHSA-2019:2091 (opens in a new tab)
- access.redhat.com/errata/RHSA-2019:3222 (opens in a new tab)
- access.redhat.com/errata/RHSA-2020:0593 (opens in a new tab)
- lists.apache.org/thread.html/r1b103833cb5bc8466e24ff0ecc5e75b45a705334ab6a444e64e840a0%40%3Cissues.bookkeeper.apache.org%3E (opens in a new tab)
- oracle.com//security-alerts/cpujul2021.html (opens in a new tab)
- github.com/systemd/systemd/pull/10519 (opens in a new tab)