CVE-2026-6019
Published: April 25, 2026Last modified: August 1, 2026
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.1 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | REQUIRED |
| Scope | CHANGED |
| Confidentiality | LOW |
| Integrity impact | LOW |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | python3 | Not affected (3.11.3-r0) |
| 25 LTS | python3 | Unknown (3.12.10-r1) | |
| Stream | python3 | Fixed (3.14.5-r1) | |
| Hardened Containers | 23 LTS | python3 | Not affected (3.11.3-r0) |
| 25 LTS | python3 | Unknown (3.12.10-r1) | |
| Stream | python3 | Fixed (3.14.5-r1) |
References
- https://github.com/python/cpython/commit/3c59b8b53fc75c7f9578d16fb8201ceb43e8f76c
- https://github.com/python/cpython/commit/76b3923d688c0efc580658476c5f525ec8735104
- https://github.com/python/cpython/commit/f795e042043dfe26c42e1971d4502c1cdc4c65b8
- https://github.com/python/cpython/issues/90309
- https://github.com/python/cpython/pull/148848
- https://mail.python.org/archives/list/[email protected]/thread/IVNWGV2BBNC3RHQAFS22UP4DY56SAXX3/