VulnerabilityAnalyzed
CVE-2026-6019
Mitigation base64-encodes the cookie value to disallow escaping using cookie value.
LOW 2.1EPSS 0.23%
Does this matter?
Lower severity and a low EPSS score (0.23%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 2.1 LOWCVSS: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/M
- EPSS
- 0.23% probability · 14th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-150, CWE-116
- Affected
- python/python
- Source
- cna@python.org
References
- https://github.com/python/cpython/commit/3c59b8b53fc75c7f9578d16fb8201ceb43e8f76cPatch
- https://github.com/python/cpython/commit/76b3923d688c0efc580658476c5f525ec8735104Patch
- https://github.com/python/cpython/commit/f795e042043dfe26c42e1971d4502c1cdc4c65b8Patch
- https://github.com/python/cpython/issues/90309Exploit, Issue Tracking
- https://github.com/python/cpython/pull/148848Issue Tracking, Patch
- https://mail.python.org/archives/list/security-announce@python.org/thread/IVNWGV2BBNC3RHQAFS22UP4DY56SAXX3/Mailing List, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.