vulnerability / NVI-00011821 / Revision 2
virtualenv bash activate runs commands from an environment name with a backslash before $
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.
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.
7.8 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
0.263%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.18246. 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<= 21.14.6
### Summary The bash `activate` script escapes the environment name for only one of the two passes bash makes over `PS1`, so a backslash in the name undoes the escaping and a name containing `\$(...)` runs as commands in the user's shell each time bash draws the prompt. ### Affected area `src/virtualenv/activation/bash/activate.sh`, the block that prepends the environment name to `PS1`. ### Attacker-controlled input The environment name: the environment directory's name, or the `--prompt` or `VIRTUALENV_PROMPT` value. An attacker needs to influence it, for example through a CI job or wrapper tool that passes a branch, project or job name through, or a directory in a cloned repository or unpacked archive. `--prompt .` takes the current directory's name. ### Details bash handles `PS1` in two passes each time it draws the prompt: it first decodes backslash prompt escapes, turning `\\` into `\` and `\$` into `$` (or `#` for root), and then runs parameter expansion, command substitution and arithmetic expansion on the result. Since 21.13.0 the script escapes backslashes, dollar signs and backticks in the name, but only for the second pass, so the decode pass strips the escaping t
03 / Response
What to do next
- 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.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-vxj4-q4g9-crj7 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-113725 ↗
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.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.