VulnerabilityPublished 22 Apr 2026

CVE-2026-35342: Uutils coreutils · Insecure Temporary File

Affects Uutils coreutilsSource CVE Database V5

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Not known to be exploited · CVSS 3.3 Low : upgrade to 0.6.0 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

3.3Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.6.0

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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

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 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Uutils coreutils to 0.6.0.

Affected software

Product	Affected	Fixed in
Uutilscoreutils	Affected <0.6.0	Fixed in 0.6.0
GitHubuutils/coreutils`pkg:github/uutils/coreutils`Other threats	Affected =0	Fixed in–
GitHubcoreutils`pkg:github/coreutils`Other threats	Affected <0.6.0	Fixed in 0.6.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

If you cannot patch yet, users should avoid running mktemp in directories with permissive access controls or ensure TMPDIR is set to a secure directory path. Monitoring for updates from the uutils coreutils project is recommended.

Description

The mktemp utility in uutils coreutils improperly handles an empty TMPDIR environment variable by treating it as a valid path rather than falling back to /tmp. This causes temporary files to be created in the current working directory instead of a secure temporary directory. If the current directory has more permissive access controls, this behavior may lead to unintended information disclosure or unauthorized access to temporary files. The vulnerability has a low severity with a CVSS score of 3.3.

Impact

Temporary files intended to be created in a secure directory may instead be created in the current working directory, which could have weaker access controls. This increases the risk of unintended information disclosure or unauthorized access to temporary data. The impact is limited to confidentiality with no integrity or availability impact reported.

Summary

CVE-2026-35342 describes a vulnerability in the mktemp utility of uutils coreutils where an empty TMPDIR environment variable is not handled securely. Unlike GNU mktemp, which defaults to /tmp when TMPDIR is empty, uutils coreutils uses the empty string as a directory path, causing temporary files to be created in the current working directory. This insecure temporary file creation can expose sensitive data if the current directory is accessible by unauthorized users. The issue is categorized under CWE-377 (Insecure Temporary File). No known exploits or patches are currently reported.

CWE-377DEPRECATED: Insecure Temporary File (opens in a new tab)
Class weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
This entry has been deprecated. It was focused only on the affected resource (temporary file) and not the behavior or mistake that produced the insecure temporary file, which caused confusion and incorrect mappings.
MITRE does not allow mapping vulnerabilities to this entry; it groups weaknesses rather than naming one.
OWASP Cheat Sheets
Authorization (opens in a new tab)
Attack patterns
Explore for Predictable Temporary File Names (opens in a new tab)
Screen Temporary Files for Sensitive Information (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Jul 2026, 23:19 UTC

WeaknessesCWE-377

Technical details

References

Community reviews

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