# CVE-2026-113718: virtualenv: Xonsh activation literals depend on the script decoding codec


- **Severity:** High 7.1 (`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`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 20 Oct 2026
- **Updated:** 27 Oct 2026
- **Also known as:** BIT-virtualenv-2026-113718, DEBIAN-CVE-2026-113718, ECHO-af08-9935-836c, GHSA-394h-qwmc-48pf, MINI-27vf-9hpm-37hc, ROOT-APP-PYPI-CVE-2026-113718, UBUNTU-CVE-2026-113718

## What is CVE-2026-113718?

CVE-2026-113718 is a high-severity vulnerability in pypa virtualenv, published on 20 Oct 2026. 

### Official description

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, POSIX xonsh activation quote() uses repr() to write printable non-ASCII prompt or destination data into UTF-8 activate.xsh, while xonsh can read that script using $XONSH_ENCODING. Under a legacy multibyte codec such as GBK or Big5, a UTF-8 trail byte can consume the backslash before an adjacent quote, allowing the literal to close and attacker-influenced statements to execute when the user sources the generated script. This issue is fixed in version 21.14.9.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-113718?

3 open source packages ship an affected version, including virtualenv.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `virtualenv` | Bitnami | All versions | 21.14.9 |
| `virtualenv` | PyPI | All versions | 21.14.9 |
| `virtualenv` | PyPI | All versions | 21.14.9 |

## How do I fix CVE-2026-113718?

Upgrade virtualenv to 21.14.9 or later.

## Is CVE-2026-113718 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-113718 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-113718 and fix it if it is affected.

What it is: CVE-2026-113718 is a high-severity vulnerability in pypa virtualenv, published on 20 Oct 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-113718 exists.

Affected packages and fixed versions:
- virtualenv (Bitnami): affected all versions; fixed in 21.14.9
- virtualenv (PyPI): affected all versions; fixed in 21.14.9
- virtualenv (PyPI): affected all versions; fixed in 21.14.9

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-113718/ (Markdown: https://insights.sbomify.com/CVE-2026-113718/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-113718
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-113718
- OSV: https://osv.dev/vulnerability/CVE-2026-113718

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-113718/
Summaries are generated and may contain mistakes; the official description above is the record.