SourcelessFileLoader does not use io.open_code()
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.7epss 0.2%
exploitation probability
0.2%top 88% of all CVEs
observed exploitation
nono source reports it
The import hook in CPython that handles legacy *.pyc files (SourcelessFileLoader) is incorrectly handled in FileLoader (a base class) and so does not use io.open_code() to read the .pyc files. sys.audit handlers for this audit event therefore do not fire.
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Affected products
Python Software Foundation · CPythonReferences
https://github.com/python/cpython/commit/482d6f8bdba9da3725d272e8bb4a2d25fb6a603ehttps://github.com/python/cpython/commit/69ddd9bb2cc4bd69b1565647c18659c6a789ccd9https://github.com/python/cpython/commit/876858c9f65d9ab656c7fa639f268ce7856d89ddhttps://github.com/python/cpython/commit/a51b1b512de1d56b3714b65628a2eae2b07e535ehttps://github.com/python/cpython/commit/c70adad78caeeea33f92f560ecb93331ca11bf66https://github.com/python/cpython/commit/e58e9802b9bec5cdbf48fc9bf1da5f4fda482e86https://github.com/python/cpython/issues/145506https://github.com/python/cpython/pull/145507http://www.openwall.com/lists/oss-security/2026/03/05/6