SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-113732

An attacker-influenced environment path, --prompt, or VIRTUALENV_PROMPT value containing a backslash before a quote can therefore terminate the generated fish literal and execute command substitution when the user sources activate.fish.

HIGH 7.8EPSS 0.24%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.2, FishActivator inherits ViaTemplateActivator.quote(), which uses POSIX shlex.quote() even though fish interprets backslashes and single quotes differently. An attacker-influenced environment path, --prompt, or VIRTUALENV_PROMPT value containing a backslash before a quote can therefore terminate the generated fish literal and execute command substitution when the user sources activate.fish. This issue is fixed in version 21.14.2.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
0.24% probability · 15th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-78, CWE-116
Source
security-advisories@github.com
EPSS trend
0%3%5%21 October 2026: 0.21%26 October 2026: 0.24%21 October 202626 October 2026

EPSS moved from 0.2% on 21 October 2026 to 0.2% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.