Use-after-free in "unicode_escape" decoder with error handler
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.9epss 0.2%
exploitation probability
0.2%top 88% of all CVEs
observed exploitation
nono source reports it
There is an issue in CPython when using `bytes.decode("unicode_escape", error="ignore|replace")`. If you are not using the "unicode_escape" encoding or an error handler your usage is not affected. To work-around this issue you may stop using the error= handler and instead wrap the bytes.decode() call in a try-except catching the DecodeError.
CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
Python Software Foundation · CPythonReferences
https://github.com/python/cpython/commit/4398b788ffc1f954a2c552da285477d42a571292https://github.com/python/cpython/commit/6279eb8c076d89d3739a6edb393e43c7929b429dhttps://github.com/python/cpython/commit/69b4387f78f413e8c47572a85b3478c47eba8142https://github.com/python/cpython/commit/73b3040f592436385007918887b7e2132aa8431fhttps://github.com/python/cpython/commit/8d35fd1b34935221aff23a1ab69a429dd156be77https://github.com/python/cpython/commit/9f69a58623bd01349a18ba0c7a9cb1dad6a51e8ehttps://github.com/python/cpython/commit/ab9893c40609935e0d40a6d2a7307ea51aec598bhttps://github.com/python/cpython/issues/133767https://github.com/python/cpython/pull/129648https://mail.python.org/archives/list/security-announce@python.org/thread/L75IPBBTSCYEF56I2M4KIW353BB3AY74/http://www.openwall.com/lists/oss-security/2025/05/16/4http://www.openwall.com/lists/oss-security/2025/05/19/1