VulnerabilityPublished 22 Oct 2026Updated 29 Oct 2026

CVE-2026-113722: virtualenv · Generated POSIX console launchers interpret destination paths as shell syntax

Affects virtualfishSource GCVE Database

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Authoritative record:CVE-2026-113722· High 7.8

Not known to be exploited · CVSS 7.8 High : upgrade to 2.5.9_5 soon.

Data as of 30 Oct 2026, 07:30 UTC

CVSS 3.1 base score

7.8High

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	7.8

Patch: Available – fixed in 2.5.9_5

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

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

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
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 impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Oct 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 29 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 virtualfish to 2.5.9_5.

Affected software

Product	Affected	Fixed in
Homebrewvirtualfish`pkg:brew/virtualfish`Other threats	Affected >=2.5.5 <2.5.9_5	Fixed in 2.5.9_5

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

Description

## Summary A destination path supplied to virtualenv can be interpreted as shell syntax by a generated POSIX console launcher. The app-data seeder and pip delegate launcher generation to distlib but supply the interpreter path in a form that does not preserve it as literal data in the shell wrapper. ## Affected area POSIX console scripts generated by the app-data seeder or pip when the interpreter path requires a shell wrapper. Windows executable launchers are not affected by this path. ## Attacker-controlled input An attacker must influence the environment destination passed to virtualenv, and the user must subsequently run a generated launcher. The attacker does not need to modify an installed executable or control the user's app-data cache. ## Affected code The relevant 21.14.8 source is in [ScriptMakerCustom](https://github.com/pypa/virtualenv/blob/a795ab116356afde11039cf2763d77e8a06da738/src/virtualenv/seed/embed/via_app_data/pip_install/base.py). ## Mechanism The app-data seeder passes the environment's interpreter path through `enquote_executable()` to distlib's `ScriptMaker`. It adds double quotes for a path with a space but does not escape shell expansions inside those quotes. When the path has a space or the shebang exceeds 127 bytes, distlib emits a `#!/bin/sh` wrapper with a line shaped like `'''exec' "<path>" "$0" "$@"`. The shell expands `$(...)` and backticks in that path when the launcher is run. The same wrapper must also parse as Python, which exposes additional quote and backslash cases. Environment creation and activation do not trigger the shell payload. ## Reproduction and evidence The scanner created three environments: a control under `my -touch PWNED- project`, one under `my $(touch PWNED) project`, and one under a path of more than 127 bytes ending in `$(touch${IFS}PWNED)`. Each was created without producing `PWNED`. Running the generated `bin/pip --version` created `PWNED` in both attack cases; the control created none. The long-path case reached the shell wrapper without a space. This reproduces execution by the generated launcher, with the user's privileges, rather than during seeding. The report dates the app-data seeder's distlib launcher integration to #1579, first released in 20.0.2. [PR #3417](https://github.com/pypa/virtualenv/pull/3417) quotes the raw interpreter path for the POSIX wrapper and repairs launchers written by the pip seeder. Pip's own distlib can write a vulnerable wrapper again during a later pip install or upgrade; the proposed virtualenv fix does not change pip's vendored code. The maintainer-provided follow-up review reports that later path separately. ## Attack sequence ```mermaid sequenceDiagram participant A as Destination supplier participant V as virtualenv seeder participant D as distlib ScriptMaker participant S as Generated bin/pip participant U as User A->>V: path contains $(touch PWNED) V->>D: pass interpreter path with incomplete shell quoting D->>S: write /bin/sh wrapper Note over V,S: no payload runs during creation or activation U->>S: pip --version S->>S: shell expands path and runs touch S-->>U: PWNED appears with user's privileges ``` ## Reproducer files The following files are from the scanner report for `ANT-2026-5DZVLGL1`. They were tested against commit `a857a7823c73` in the scanner image. The `repro` entrypoint expects companion files under `/tmp/repro.d`; cases that change user IDs need a disposable root-capable container. The last output line is `BUG` when the reported behavior occurs. These files are included as evidence and were not rerun for this advisory update. **`repro`** ```text #!/usr/bin/env python3 import shutil import subprocess from pathlib import Path WORK = Path("/tmp/repro-console-script") # The attacker's whole input: the name of a directory above the environment (a repository, a project folder). DIRECTORY_NAMES = { "CONTROL": "my -touch PWNED- project", "OBSERVED": "my $(touch PWNED) project", # no space: distlib also picks the /bin/sh launcher once "#!<dest>/bin/python" is longer than 127 bytes "OBSERVED_LONG": "p" * 120 + "$(touch${IFS}PWNED)", } shutil.rmtree(WORK, ignore_errors=True) pip_printed = {} created_by_pip = {} for label, name in DIRECTORY_NAMES.items(): # the payload can hold no "/", so it touches a relative PWNED: each case gets its own empty working directory cwd = WORK / label / "cwd" venv = WORK / label / name / "venv" cwd.mkdir(parents=True) # set up: the user creates an environment there with default options (--no-periodic-update keeps it offline) subprocess.run(["virtualenv", "--quiet", "--no-periodic-update", str(venv)], cwd=cwd, check=True) assert list(cwd.iterdir()) == [], "environment creation must not have created anything" # trigger: the user runs the seeded pip; argv is a list, so the only shell that reads the name is bin/pip's own pip = subprocess.run([venv / "bin"

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