7.8

CVE-2026-42171: nullsoft nullsoft scriptable install system Uncontrolled Search Path Element

CVSS: 7.8v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-42171DEBIAN-CVE-2026-42171
Published 24-04-2026Last modified 25-04-2026
Open JSON

Vulnerability summary

CVE-2026-42171 is a high (CVSS 7.8) Uncontrolled Search Path Element vulnerability in nullsoft nullsoft scriptable install system. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 14% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.24%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 24-04-2026
    PublishedVulnerability first disclosed.
  2. 25-04-2026
    Last modifiedVulnerability information updated.

Description

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 metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.24%

Chance of exploitation in the next 30 days

Percentile

14%

Versus all other CVEs

30-day change

+0.03 pp

From 0.21% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.24%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • nsisAll versions (No fix recorded) | < 3.12-1
Nullsoft1 product
Ubuntu1 product
  • nsisAll versions (No fix recorded)

3 vendors · 3 products

References

7 links