CVE-2026-42171
highpriority · track · 0EPSS 0.002 · 11 %ileEUUSEPSS · scored 2026-10-28
NSIS (Nullsoft Scriptable Install System) 3.06.1 before 3.12 sometimes uses the Low IL temp directory when executing as SYSTEM, allowing local attackers to gain privileges (if they can cause my_GetTempFileName to return 0, as shown in the references).
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (2)
Products and version ranges known to be affected.
- nullsoft nullsoft scriptable install system3.06.1 → 3.12nvdUScpe:2.3:a:nullsoft:nullsoft_scriptable_install_system:*:*:*:*:*:*:*:*
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (11)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2026-42171cnnvd
- https://github.com/NSIS-Dev/nsis/releases/tag/v312Patchcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2026-42171cnnvd
- https://github.com/NSIS-Dev/nsis/blob/7359413009afd4f0fff472d841fc2f2cc0e0a5f8/Source/exehead/util.c#L475-L484enisa_euvd
- https://github.com/NSIS-Dev/nsis/commit/8e6f02205d5f22da6c7855dbfe59b2af667330caenisa_euvd
- https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-gettempfilenameenisa_euvd
- https://nsis.sourceforge.io/Docs/AppendixF.html#v3.12-clenisa_euvd
- https://github.com/NSIS-Dev/nsis/blob/7359413009afd4f0fff472d841fc2f2cc0e0a5f8/Source/exehead/util.c#L475-L484Productnvd
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