In the Tarfile.extract() function, the filter parameter is not passed properly when extracting hardlinks. An affected system that extracts content from untrusted tar files could end up writing files with an unexpected uid/gid despite the user passing filter='data' to the extract() function.
Высокий · CVSS 8.2EPSS 0,71%Нет опубликованного исправления
tarfile opened in streaming mode mishandles EOF
When using the "tarfile" module with a file opened in "streaming mode" (mode="r|") the tarfile module did not properly handle EOF, making archive parsing take exponentially longer.
Средний · CVSS 4.1EPSS 0,13%Нет опубликованного исправления
Configuration Injection via Carriage Return (\r) in write() method
When using the "configparser" module to write configuration files
containing multi-line text values with carriage return characters (\r) the
resulting file could be injected with unexpected keys and values if the
attacker controls the written value.
Высокий · CVSS 7.8EPSS 0,75%Нет опубликованного исправления
tarfile extraction filter bypass allows escaping the destination directory
tarfile.extractall() with the 'data' or 'tar'
filter could be bypassed by a crafted archive where a hardlink
references a symlink stored at a deeper name than the hardlink itself.
The extraction fallback validated the symlink at it's archived location
but recreated it at the hardlink's shallower
path, letting a relative
target the filter judged contained escape the destination directory.
This allowed a malicious tar archive to create a symlink pointing
outside the destination, enabling out-of-destination file reads or
writes. This was an incomplete fix of CVE-2025-4330.
bz2.BZ2Decompressor reuse after error can cause a stack buffer overflow
bz2.BZ2Decompressor objects could be reused after a decompression error. If an application caught the resulting OSError and retried with the same decompressor, crafted input could cause the decompressor to resume from an invalid internal state and perform out-of-bounds writes to a stack buffer. This could crash the process when processing untrusted data.
tarfile.data_filter path traversal bypass allows writing outside the extraction directory
tarfile.data_filter could be bypassed using crafted link entries, including symlinks with empty or directory-like names, to redirect later archive members outside the intended extraction directory. This allowed a malicious tar archive to cause tarfile.extractall() to write files outside the destination directory, subject to the permissions of the extracting process.
Potential DoS via quadratic complexity in unicodedata.normalize()
unicodedata.normalize() can take excessive CPU time when processing
specially crafted Unicode input containing long runs of combining characters
with alternating Canonical Combining Class values.
This affects all normalization forms.
FTP PASV SSRF, ftpcp() does not use actual peer address, trusts server-supplied PASV host address
The ftpcp() function in Lib/ftplib.py was not updated when
CVE-2021-4189 was fixed. While makepasv() was patched to replace
server-supplied PASV host addresses with the actual peer address
(getpeername()[0]), ftpcp() still calls parse227() directly and passes
the raw attacker-controllable IP address and port to target.sendport(). This patch is related to CVE-2021-4189.
Средний · CVSS 6.3EPSS 0,67%Нет опубликованного исправления
The expat and elementtree parsers use insufficient entropy for XML hash-flooding protection
`xml.parsers.expat` and `xml.etree.ElementTree` use insufficient entropy for Expat hash-flooding protection, which allows a crafted XML document to trigger hash flooding.\r\n\r\nFully mitigating this vulnerability requires both updating libexpat to 2.8.0 or later and applying this patch.
BaseCookie.js_output() does not neutralize embedded characters
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.
Out-of-bounds read/write during remote profiling and asyncio process introspection when connecting to malicious target
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 process if that process connected to a malicious or "infected" Python process via the remote debugging feature. This vulnerability requires persistently and repeatedly connecting to the process to be exploited, even after the connecting process crashes with high likelihood due to ASLR.
Incomplete mitigation of CVE-2026-4519, %action expansion for command injection to webbrowser.open()
Mitgation of CVE-2026-4519 was incomplete. If the URL contained "%action" the mitigation could be bypassed for certain browser types the "webbrowser.open()" API could have commands injected into the underlying shell. See CVE-2026-4519 for details.
Use-after-free in lzma.LZMADecompressor, bz2.BZ2Decompressor, and gzip.GzipFile after re-use under memory pressure
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. This scenario can be triggered if the process is under memory pressure. The fix cleans up the dangling pointer in this specific error condition.
The vulnerability is only present if the program re-uses decompressor instances across multiple decompression calls even after a `MemoryError` is raised during decompression. Using the helper functions to one-shot decompress data such as `lzma.decompress()`, `bz2.decompress()`, `gzip.decompress()`,
email BytesGenerator header injection due to unquoted newlines
The
email module, specifically the "BytesGenerator" class, didn’t properly quote newlines for email headers when
serializing an email message allowing for header injection when an email
is serialized. This is only applicable if using "LiteralHeader" writing headers that don't respect email folding rules, the new behavior will reject the incorrectly folded headers in "BytesGenerator".
When passing data to the b64decode(), standard_b64decode(), and urlsafe_b64decode() functions in the "base64" module the characters "+/" will always be accepted, regardless of the value of "altchars" parameter, typically used to establish an "alternative base64 alphabet" such as the URL safe alphabet. This behavior matches what is recommended in earlier base64 RFCs, but newer RFCs now recommend either dropping characters outside the specified base64 alphabet or raising an error. The old behavior has the possibility of causing data integrity issues.
This behavior can only be insecure if your application uses an alternate base64 alphabet (w
Use-after-free in "unicode_escape" decoder with error handler
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.