CVE-2026-6019
MEDIUM6.1EPSS 0.03%BaseCookie.js_output() does not neutralize embedded characters
Published: 4/22/2026Modified: 5/23/2026
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.
Affected packages (8)
- Bitnami/libpythonfrom 0, < 3.14.5
- Bitnami/pythonfrom 0, < 3.14.5
- Bitnami/python-minfrom 0, < 3.14.5
- Debian/pypy3from 0
- Debian/python3.11from 0
- Debian/python3.13from 0, < 3.13.5-2+deb13u2
- Debian/python3.14from 0, < 3.14.5~rc1-1
- Debian/python3.9from 0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
References (8)
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-6019
- WEBhttps://github.com/python/cpython/commit/3c59b8b53fc75c7f9578d16fb8201ceb43e8f76c
- WEBhttps://github.com/python/cpython/commit/76b3923d688c0efc580658476c5f525ec8735104
- WEBhttps://github.com/python/cpython/commit/f795e042043dfe26c42e1971d4502c1cdc4c65b8
- WEBhttps://github.com/python/cpython/issues/90309
- WEBhttps://github.com/python/cpython/pull/148848
- WEBhttps://mail.python.org/archives/list/[email protected]/thread/IVNWGV2BBNC3RHQAFS22UP4DY56SAXX3/
- WEBhttps://nvd.nist.gov/vuln/detail/CVE-2026-6019