VulnerabilityPublished 1 Apr 2026

CVE-2026-5271: Python Software Foundation pymanager · Uncontrolled Search Path Element

Affects Python Software Foundation pymanagerSource CVE Database V5

Compare

Not known to be exploited · CVSS 5.6 Medium : upgrade to 26.1 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score

5.6Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 26.1

CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Attack Vector: Local
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: Active
Vulnerable system confidentiality: None
Vulnerable system integrity: High
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Local: The vulnerable system 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 through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: Active: Successful exploitation of this vulnerability requires a targeted user to perform specific, conscious interactions with the vulnerable system and the attacker’s payload, or the user’s interactions would actively subvert protection mechanisms which would lead to exploitation of the vulnerability.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 1 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 Python Software Foundation pymanager to 26.1.

Affected software

Product	Affected	Fixed in
Python Software Foundationpymanager	Affected >=26.0 <26.1	Fixed in 26.1
PyPIpymanager`pkg:pypi/pymanager`Other threats	Affected =26.0	Fixed in–
GitHubpymanager`pkg:github/pymanager`Other threats	Affected >=26.0 <26.1	Fixed in 26.1

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

AI-suggested

To mitigate CVE-2026-5271, organizations should implement the following specific measures: 1) Avoid running pymanager in directories where untrusted users can write files; restrict write permissions on working directories to trusted users only. 2) Use virtual environments or containerization to isolate Python execution environments and control sys.path contents explicitly. 3) Modify or patch pymanager to exclude the current working directory from sys.path or to prioritize trusted module paths over the CWD. 4) Implement file integrity monitoring on working directories to detect unauthorized module additions or changes. 5) Educate developers and system administrators about the risks of module shadowing and enforce secure coding and deployment practices. 6) Monitor runtime environments for unexpected module loads or suspicious behavior indicative of shadowed modules. 7) If possible, upgrade pymanager to a version that addresses this vulnerability once available. These steps go beyond generic advice by focusing on controlling the working directory environment and sys.path management.

Description

pymanager included the current working directory in sys.path meaning modules could be shadowed by modules in the current working directory. As a result, if a user executes a pymanager-generated command (e.g., pip, pytest) from an attacker-controlled directory, a malicious module in that directory can be imported and executed instead of the intended package.

Impact

The primary impact of CVE-2026-5271 is on the integrity of Python applications using pymanager. If an attacker can place a malicious module in the current working directory, they can cause pymanager to load and execute this malicious code instead of the intended module, potentially leading to unauthorized code execution or manipulation of application behavior. This can compromise the trustworthiness of the application and lead to further exploitation, such as privilege escalation or data manipulation. Since exploitation requires local access and user interaction, remote attackers cannot directly exploit this vulnerability, limiting its scope. However, in environments with multiple users or automated processes that run pymanager scripts, the risk increases. The vulnerability does not affect confidentiality or availability directly but can indirectly lead to data corruption or unauthorized actions. Organizations relying on pymanager for critical Python workflows or automation may face operational risks if this vulnerability is exploited.

Summary

CVE-2026-5271 identifies a vulnerability in the Python Software Foundation's pymanager package, specifically related to the inclusion of the current working directory (CWD) in the sys.path module search path. In Python, sys.path determines the order in which modules are searched and loaded. By including the CWD, pymanager allows modules located in the current directory to shadow or override standard library or installed modules. This can lead to a situation where an attacker with the ability to place a malicious module in the working directory causes pymanager to load that malicious module instead of the legitimate one. The vulnerability is classified with a CVSS 4.0 base score of 5.6 (medium severity), reflecting that exploitation requires local access (AV:L), low attack complexity (AC:L), no privileges (PR:N), but user interaction (UI:A) is needed. The impact primarily affects integrity (VI:H), with no direct impact on confidentiality or availability. The vulnerability does not require authentication but does require the user to execute or interact with the vulnerable environment. No patches or known exploits are currently reported. This vulnerability is particularly relevant in environments where pymanager is used in development or runtime contexts where the working directory is not tightly controlled, such as shared or multi-user systems, or automated build and deployment pipelines.

CWE-427Uncontrolled Search Path Element (opens in a new tab)
Base weaknessOWASP Top 10 A08:2025: Software or Data Integrity Failures (opens in a new tab)
The product uses a fixed or controlled search path to find resources, but one or more locations in that path can be under the control of unintended actors.
Architecture and Design · Implementation · Attack Surface Reduction
Hard-code the search path to a set of known-safe values (such as system directories), or only allow them to be specified by the administrator in a configuration file. Do not allow these settings to be modified by an external party. Be careful to avoid related weaknesses such as CWE-426 and CWE-428.
Implementation · Attack Surface Reduction
When invoking other programs, specify those programs using fully-qualified pathnames. While this is an effective approach, code that uses fully-qualified pathnames might not be portable to other systems that do not use the same pathnames.
Implementation · Attack Surface Reduction
Remove or restrict all environment settings before invoking other programs. This includes the PATH environment variable, LD_LIBRARY_PATH, and other settings that identify the location of code libraries, and any application-specific search paths.
OWASP Cheat Sheets
Software Supply Chain Security (opens in a new tab)
Infrastructure as Code (opens in a new tab)
Attack patterns
Leveraging/Manipulating Configuration File Search Paths (opens in a new tab)
Search Order Hijacking (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Apr 2026, 14:24 UTC

WeaknessesCWE-427

Technical details

References

Community reviews

Related threats