{"id":"CVE-2025-13836","title":"When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length","summary":"When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially ca…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-400"],"vendor":"python","product":"python","affected":["python < 3.10.20","python >= 3.11.0, < 3.11.15","python >= 3.12.0, < 3.12.13","python >= 3.13.0, < 3.13.11","python = 3.14.0","python = 3.15.0"],"patched":["python 3.13.11"],"published":"2025-12-01","updated":"2026-09-03","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-13836","references":[{"url":"https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628","label":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15","label":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155","label":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5","label":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/5dc101675fd22918facbbe0fecdc821502beaaf0","label":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/afc40bdd3dd71f343fd9016f6d8eebbacbd6587c","label":"cna@python.org"},{"url":"https://github.com/python/cpython/issues/119451","label":"cna@python.org"},{"url":"https://github.com/python/cpython/pull/119454","label":"cna@python.org"},{"url":"https://mail.python.org/archives/list/security-announce@python.org/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/","label":"cna@python.org"}],"tags":["nvd"],"epss":0.01631,"epssPercentile":0.75204,"ingestedAt":"2026-09-03T03:55:23.777Z","slug":"CVE-2025-13836","body":"## Overview\n\nWhen reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS.\n\n## Affected\n\n- `python < 3.10.20`\n- `python >= 3.11.0, < 3.11.15`\n- `python >= 3.12.0, < 3.12.13`\n- `python >= 3.13.0, < 3.13.11`\n- `python = 3.14.0`\n- `python = 3.15.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `python 3.13.11`","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":41.3,"likelihood":0.3,"exploitation":0,"ransomware":0},"changes":[]}