# CVE-2026-6019: BaseCookie.js_output() does not neutralize embedded characters

> An attacker can inject malicious scripts via cookie values due to insufficient escaping in Python's http.cookies module, leading to XSS.

- **Severity:** Low 2.1 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Apr 2026
- **Updated:** 10 Jun 2026
- **Also known as:** AZL-109716, AZL-84728, BELL-CVE-2026-6019, BIT-libpython-2026-6019, BIT-python-2026-6019, BIT-python-min-2026-6019, CLSA-2026-1780400093, CLSA-2026-1780481964, CLSA-2026-1780497150, CLSA-2026-1780498704, DEBIAN-CVE-2026-6019, ECHO-1e4c-228c-95ee, GHSA-2755-2mm4-rm5c, MINI-4pxg-f66m-j7fv, MINI-4xv9-2j3q-2vmp, MINI-87fm-mqwf-q5mg, MINI-jpp5-55pm-p7m5, MINI-pffr-5h4j-f65v, OESA-2026-2269, OESA-2026-2270, OESA-2026-2271, PSF-2026-21, RHSA-2026:22952, RHSA-2026:32980, RHSA-2026:32997, RHSA-2026:33885, ROOT-OS-DEBIAN-11-CVE-2026-6019, UBUNTU-CVE-2026-6019

## What is CVE-2026-6019?

CVE-2026-6019 is a low-severity cross-site scripting vulnerability in Python Python, published on 22 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

http.cookies.Morsel.js_output() returns an inline <script> snippet and only escapes " for JavaScript string context. It does not neutralize the HTML parser-sensitive sequence </script> inside the generated script element. Mitigation base64-encodes the cookie value to disallow escaping using cookie value.

Weakness: CWE-116 (Improper Encoding or Escaping of Output), CWE-150 (Improper Neutralization of Escape, Meta, or Control Sequences)

## Which versions are affected by CVE-2026-6019?

3 open source packages ship an affected version, including libpython, python and python-min. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libpython` | Bitnami | All versions | 3.13.14, 3.14.5 |
| `python` | Bitnami | All versions | 3.13.14, 3.14.5 |
| `python-min` | Bitnami | All versions | 3.13.14, 3.14.5 |
| `python-unversioned-command` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3-debug` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3-devel` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3-idle` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3-libs` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3-test` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3-tkinter` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3.11` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.3.hum1 |
| `python3.11-debug` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.3.hum1 |
| `python3.11-devel` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.3.hum1 |
| `python3.11-idle` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.3.hum1 |
| `python3.11-libs` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.3.hum1 |
| `python3.11-test` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.3.hum1 |
| `python3.11-tkinter` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.3.hum1 |
| `python3.12` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.2.hum1 |
| `python3.12-debug` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.2.hum1 |
| `python3.12-devel` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.2.hum1 |
| `python3.12-idle` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.2.hum1 |
| `python3.12-libs` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.2.hum1 |
| `python3.12-test` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.2.hum1 |
| `python3.12-tkinter` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.2.hum1 |
| `python3.13` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.1.hum1 |
| `python3.13-debug` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.1.hum1 |
| `python3.13-devel` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.1.hum1 |
| `python3.13-freethreading` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.1.hum1 |
| `python3.13-freethreading-debug` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.1.hum1 |
| `python3.13-idle` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.1.hum1 |
| `python3.13-libs` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.1.hum1 |
| `python3.13-test` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.1.hum1 |
| `python3.13-tkinter` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.1.hum1 |
| `python3.14` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3.14-freethreading` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3.14-freethreading-debug` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3.14-freethreading-devel` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3.14-freethreading-idle` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |
| `python3.14-freethreading-libs` | Red Hat:hummingbird:1 | All versions | 0:3.14.5-2.hum1 |

Products: Python Python.

## How do I fix CVE-2026-6019?

Upgrade libpython to a fixed version for your release line: 3.13.14 or 3.14.5.

## Is CVE-2026-6019 being exploited?

There is no known exploitation of CVE-2026-6019 in the wild and no public exploit code.

## Other vulnerabilities in Python Python

- [CVE-2008-5031](https://insights.sbomify.com/CVE-2008-5031/): Integer overflow in n/a (critical 10.0)
- [CVE-2014-4650](https://insights.sbomify.com/CVE-2014-4650/): Path traversal in n/a (critical 9.8)
- [CVE-2016-5636](https://insights.sbomify.com/CVE-2016-5636/): Integer overflow in n/a (critical 9.8)
- [CVE-2007-4559](https://insights.sbomify.com/CVE-2007-4559/): Path traversal in n/a (critical 9.8)
- [CVE-2017-17522](https://insights.sbomify.com/CVE-2017-17522/): Command injection in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6019 and fix it if it is affected.

What it is: CVE-2026-6019 is a low-severity cross-site scripting vulnerability in Python Python, published on 22 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-6019 in the wild and no public exploit code.

Affected packages and fixed versions:
- libpython (Bitnami): affected all versions; fixed in 3.13.14, 3.14.5
- python (Bitnami): affected all versions; fixed in 3.13.14, 3.14.5
- python-min (Bitnami): affected all versions; fixed in 3.13.14, 3.14.5

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-2026-6019/ (Markdown: https://insights.sbomify.com/CVE-2026-6019/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6019
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6019
- OSV: https://osv.dev/vulnerability/CVE-2026-6019

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6019/
Summaries are generated and may contain mistakes; the official description above is the record.