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CVE-2026-6019
BaseCookie.js_output() does not neutralize embedded characters
Low2.1EPSS 0.21%
- Published
- Updated
- Reserved
- Assigned by
- PSF
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| PSFCNA (assigner) | 4.0 | Low2.1 | 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 |
| NVDNVD · Analyzed | 4.0 | Low2.1 | 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/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 |
- EPSS (exploitation in 30 days)
- 0.21% · top 89% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.1.
Weakness
Affected products
Python Software Foundation · CPython
- affected < 3.13.14
- affected 3.14.0a1 – < 3.14.5rc1
- affected 3.15.0a1 – < 3.15.0b1
References (6)
- https://github.com/python/cpython/pull/148848 (opens in a new tab)patch
- https://github.com/python/cpython/issues/90309 (opens in a new tab)issue-tracking
- https://mail.python.org/archives/list/[email protected]/thread/IVNWGV2BBNC3RHQAFS22UP4DY56SAXX3/ (opens in a new tab)vendor-advisory
- https://github.com/python/cpython/commit/76b3923d688c0efc580658476c5f525ec8735104 (opens in a new tab)patch
- https://github.com/python/cpython/commit/3c59b8b53fc75c7f9578d16fb8201ceb43e8f76c (opens in a new tab)patch
- https://github.com/python/cpython/commit/f795e042043dfe26c42e1971d4502c1cdc4c65b8 (opens in a new tab)patch
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-6019)Record last updated .