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CVE-2026-54161

8.1 highEPSS 0.6%

High (8.1). EPSS 0.6% estimated probability of exploitation activity in the next 30 days.

On this page
Network UPS Tools is a collection of programs which provide a common interface for monitoring and administering UPS, PDU and SCD hardware. From 2.8.3 to 2.8.5, upsmon in clients/upsmon.c inserts the server-supplied ups.alarm value into shell commands executed by notify(), async_notify(), and wall(). When a monitored device reports an ALARM state and an operator has configured NOTIFYCMD with EXEC in NOTIFYFLAG ALARM, shell metacharacters in the alarm text are evaluated on POSIX or Windows and can execute arbitrary operating-system commands as the upsmon account, which is commonly root. An attacker can control the value through a malicious or compromised upsd, a man-in-the-middle on a plaintext upsd to upsmon connection, or a compromised UPS device whose driver supplies the alarm upstream of upsd; TLS between upsd and upsmon does not mitigate the compromised-device path. This vulnerability is fixed in 2.8.6.

Severity

CVSS 3.1

8.1 high
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.6% estimated probability of exploitation activity in the next 30 days; 51st percentile. Scored 2026-11-04. A forecast for this CVE across the internet, not for your own systems.
CISA's assessment (SSVC)
Exploitation: none · Automatable: no · Technical impact: total, assessed 2026-11-03. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
CWE
CWE-78 Improper Neutralization of Special Elements used in an OS Command (OS Command Injection)
OWASP Top 10
A05:2025 Injection
Published
Modified
Record from
the NVD, synced

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Versions

From the CNA's record in the CVE List.

ProductAffected
networkupstools nut>= 2.8.3, <= 2.8.5

Linux distributions

DistributionReleasePackageFixed inAdvisory
Debian12, 13, 14nutno fix listedDEBIAN-CVE-2026-54161
Ubuntu25.10, 26.04:LTS, 26.10nutno fix listedUBUNTU-CVE-2026-54161
openSUSETumbleweednut2.8.5-2.1openSUSE-SU-2026:11367-1

From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0; SUSE security data, CC BY 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu · openSUSE.

Attack patterns (CAPEC)

  • CAPEC-6 Argument Injection Likelihood: High · Severity: High
  • CAPEC-15 Command Delimiters Likelihood: High · Severity: High
  • CAPEC-43 Exploiting Multiple Input Interpretation Layers Likelihood: Medium · Severity: High
  • CAPEC-88 OS Command Injection Likelihood: High · Severity: High
  • CAPEC-108 Command Line Execution through SQL Injection Likelihood: Low · Severity: Very High

The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.

References

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