RHSA-2026:19019

Use-after-free (UAF) was possible in the `lzma.LZMADecompressor`, `bz2.BZ2Decompressor`, and `gzip.GzipFile` when a memory allocation fails with a `MemoryError` and the decompression instance is re-used.

Mitgation of CVE-2026-4519 was incomplete.

The webbrowser.open() API would accept leading dashes in the URL which could be handled as command line options for certain web browsers.

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs.

The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete.

User-controlled header names and values containing newlines can allow injecting HTTP headers.

CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host.

The "profiling.sampling" module (Python 3.15+) and "asyncio introspection capabilities" (3.14+, "python -m asyncio ps" and "python -m asyncio pstree") features could be used to read and write addresses in a privileged pr…

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.