Uncontrolled recursion in systemd
Priority LOW 28CWE-674Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Deferred Red Hat: fix deferred
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-674.
Summary
A flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time when too many nested directories are created in /tmp.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01735 77th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Deferred Red Hat: fix deferred
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | systemd | Fixed in v251-rc1 | — | No fix listed | CNA |
- systemd Vendor— Affected Fixed in v251-rc1 Fixed in — No fix listed CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* | 240 to before 250.2 | Vulnerable | systemd |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 34 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* | 35 | Vulnerable | Fedoraproject |
| cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Red Hat |
- cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* Versions 240 to before 250.2 Vulnerable ·systemd
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* Versions 35 Vulnerable ·Fedoraproject
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3997
- 2026-10-03 Alias added: GHSA-4p54-q58q-8mpc
- 2026-11-02 CISA SSVC decision points changed
References
Sources
- CVE-2021-3997 · CVE Program
- CVE-2021-3997 · NVD
- FIRST EPSS
- GHSA-4p54-q58q-8mpc · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3997 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences