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vulnerability / NVI-00010712 / Revision 3

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)

GitHub lists this reviewed advisory for virtualenv. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.

source listedactiveGHSA-cx6f-vjhg-g3ccCVE-2026-115586

This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.

01 / Meaning

Why it matters

Published affected context helps an owner decide what evidence to gather. This report has not examined your application.

EPSS

0.271%

FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.19367. Missing scores are unknown.

As of · FIRST EPSS

02 / Applicability

The affected context

Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.

virtualenv

source listed
  • >= 21.14.9, < 21.14.13

## Summary The bash activator puts the caller-supplied prompt value into `PS1` unescaped whenever `promptvars` is off at activation time, and assumes prompt expansion can never run afterwards. `promptvars` and posix mode are runtime shell state, not a property of the activation moment: re-enabling prompt expansion in the same shell (`shopt -s promptvars`, `set -o posix`) or starting an interactive child bash that inherits the exported `PS1` makes bash expand the stored value and run the command substitution in it. An attacker who controls the prompt value gets command execution as the user who sources `bin/activate`. This is a regression. 21.14.8 escaped `$` and the backtick unconditionally and stays inert under the same sequence. The 21.14.9 fix for GHSA-6w3r-xr62-4xcp (#3418) rewrote that block and left bash with a path that stores the raw value whenever `promptvars` is off. ## Affected area Activation scripts (activate, activate.bat, activate.csh, activate.fish, activate.nu, Activate.ps1, activate.xsh) — specifically the bash `bin/activate`. ## Attacker-controlled input The `--prompt` value, which the security policy already lists as a value that may come from project meta

GitHub Advisory Database

03 / Response

What to do next

  1. investigate

    Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.

    Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS

A fixed release is not deployment evidence.

Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.

04 / Limits

What this report cannot establish

  • Customer inventory, deployment, reachability and exploitation have not been inspected.
  • NVD lastModified does not establish freshness of every associated CPE record.
Read the collection and interpretation limits ↗

05 / Provenance

Sources you can inspect

Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.

  1. GHSA-cx6f-vjhg-g3cc ↗

    GitHub Advisory Database · vendor advisory

    Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.

  2. CVE-2026-115586 ↗

    NIST National Vulnerability Database · official catalog

    Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.

  3. CVE-2026-115586 ↗

    FIRST EPSS · official catalog

    Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.

Public revision history

Only published revisions appear here. Routine fetches do not create a material-change event.

  1. Revision 3 ·

    Source facts changed; compare the preserved prior revision.

  2. Revision 2 ·

    Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.

  3. Revision 1 ·

    First indexed by Null; source disclosure date is shown separately.

Read the public revision data ↗

The next step is private

Bring the question into your environment.

The connected workflow is a development preview for inventory, contextual matching, owner decisions and evidence-based verification. No system-specific result is generated by this page.

See the synthetic workflow preview ↗