CVE.org (no NVD analysis yet)· CNA GitHub_M

CVE-2026-115586: virtualenv: Bash activator leaves the --prompt value unescaped in PS1 when promptvars is off, so prompt expansion later executes it (regression in 21.14.9)

HighCVSS 7.1 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 28/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.27% (FIRST EPSS).
Someone with local access to the system can trigger it. No account or password is required. Special conditions such as timing or configuration are required.
Fixed version: pypa virtualenv 21.14.13.

Low priority for now. Upgrade to pypa virtualenv 21.14.13 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

virtualenv is a tool for creating isolated virtual python environments. From 21.14.9 until 21.14.13, the bash bin/activate script can copy an attacker-controlled --prompt value into PS1 without escaping dollar signs or backticks when both promptvars and POSIX mode are disabled during activation. Re-enabling promptvars, running set -o posix, or starting an interactive child bash that inherits the exported PS1 can then expand command substitution in the stored VIRTUAL_ENV_PROMPT value and execute commands as the user who activates the environment. This issue is fixed in version 21.14.13.

Published: Oct 23, 2026
Updated: Oct 26, 2026
EPSS: 0.2% · 19th percentile
CWE: CWE-78

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 28 / 40 · 7.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 7.1; NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

pypa virtualenv
- >= 21.14.9, < 21.14.13affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
openSUSE:Tumbleweed	python-virtualenv	before 21.15.1-1.1	21.15.1-1.1
PyPI	virtualenv	from 21.14.9 · before 21.14.13	21.14.13

Same product

pypa: all records

Other highest-scoring records for the same primary product.

CVE-2026-113776virtualenv activation scripts run code from a path that contains a placeholder name
31Monitor
CVE-2026-113732virtualenv activate.fish runs commands from a path or prompt with a backslash before a quote
31Monitor
CVE-2026-113726virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST
31Monitor

Published before and after this one in the same product

← EarlierCVE-2026-113723Oct 20, 2026 · virtualenv: Bash prompt values can change meaning under older compatibility modes
28Monitor
← EarlierCVE-2026-113724Oct 20, 2026 · virtualenv: Deletion recovery can change a symlink target's mode
18Monitor
← EarlierCVE-2026-113725Oct 20, 2026 · virtualenv bash activate runs commands from an environment name with a backslash before $
31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
pypa virtualenv	21.14.13 · description	Vendor (CNA)
opensuse:python-virtualenv	21.15.1-1.1 · openSUSE:Tumbleweed	Package registry (OSV)
PyPI:virtualenv	21.14.13	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedOct 23, 2026
Fix recordedOct 23, 2026same day
TodayNov 13, 2026+21 d

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-1137223 days apartvirtualenv: Generated POSIX console launchers interpret destination paths as shell syntax
31Monitor
CVE-2026-1137253 days apartvirtualenv bash activate runs commands from an environment name with a backslash before $
31Monitor
CVE-2026-1137263 days apartvirtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST
31Monitor
CVE-2026-1137323 days apartvirtualenv activate.fish runs commands from a path or prompt with a backslash before a quote
31Monitor
CVE-2026-1137763 days apartvirtualenv activation scripts run code from a path that contains a placeholder name
31Monitor
CVE-2026-10293724 days apartvirtualenv: Command injection via --prompt in activate.bat (batch activator)
29Monitor

Not on record for this CVE: researcher credit · public bounty program.

Technical details

Attack conditions

Someone with local access to the system can trigger it.
No account or password is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality
Integrity
Availability

Attack vector: Local
Attack complexity: High
Privileges required: None
User interaction: A
Scope: X

Weakness class (CWE)

CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVSS vector

CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

User input is inserted as text into a shell command. The shell may interpret special characters in the input as part of the command.

The bug in code

The whole CWE-78 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1const host = req.body.host;
2exec("ping -c 1 " + host, onResult);

Fixed

1const host = req.body.host;
2if (!/^[a-z0-9.-]{1,253}$/i.test(host)) return res.sendStatus(400);
3execFile("ping", ["-c", "1", host], onResult);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

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Change log

SSVC exploitation— → noneOct 23, 2026, 10:07 PM UTC
Exploit maturity— → noneOct 23, 2026, 9:07 PM UTC
Fix✗ → ✓Oct 23, 2026, 9:07 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/pypa/virtualenv/commit/3598e201f6f044e389136b2347a8a919ac03c5f4

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records