Vulnerability Report

CVE-2026-6019

Title: HTTP Cookie Morsel Script Injection

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-6019.

CWE Category CWE-150

Published Date Apr 22, 2026

Modified Date May 28, 2026

Exploit Status Not Found

Score 2.1 CVSS v4.0

Exploit Probability (EPSS)

0.23%

Vulnerability Summary

CVE-2026-6019: 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.

Impacted Vendors

python 2

python_software_foundation 1

Reference Links

https://github.com/python/cpython/commit/76b3923d688c0efc580658476c5f525ec8735104 https://github.com/python/cpython/issues/90309 https://github.com/python/cpython/pull/148848 https://mail.python.org/archives/list/[email protected]/thread/IVNWGV2BBNC3RHQAFS22UP4DY56SAXX3/

CVSS v4.0

Source Entity [email protected]

Severity LOW

2.1

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

N/A

RAW VECTOR

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

CVSS v3.1

Source Entity [email protected]

Severity MEDIUM

6.1

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

REQUIRED

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns