| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| The method "sock_recvfrom_into()" of "asyncio.ProacterEventLoop" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. This allowed for an out-of-bounds buffer write if data was larger than the buffer size. Non-Windows platforms are not affected. |
| 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. |
| 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. |
| 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 (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()`, and `zlib.decompress()` are not affected as a new decompressor instance is used per call. If the decompressor instance is not re-used after an error condition, this usage is similarly not vulnerable. |
| 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. |
| CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host. |
| 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. |
| 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. |
| 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. |
| The webbrowser.open() API would accept leading dashes in the URL which
could be handled as command line options for certain web browsers. New
behavior rejects leading dashes. Users are recommended to sanitize URLs
prior to passing to webbrowser.open(). |
| When calling base64.b64decode() or related functions the decoding process would stop after encountering the first padded quad regardless of whether there was more information to be processed. This can lead to data being accepted which may be processed differently by other implementations. Use "validate=True" to enable stricter processing of base64 data. |
| On Windows a directory returned by tempfile.mkdtemp() would not always have permissions set to restrict reading and writing to the temporary directory by other users, instead usually inheriting the correct permissions from the default location. Alternate configurations or users without a profile directory may not have the intended permissions.
If you’re not using Windows or haven’t changed the temporary directory location then you aren’t affected by this vulnerability. On other platforms the returned directory is consistently readable and writable only by the current user.
This issue was caused by Python not supporting Unix permissions on Windows. The fix adds support for Unix “700” for the mkdir function on Windows which is used by mkdtemp() to ensure the newly created directory has the proper permissions. |
| DISPUTED: The project has clarified that the documentation was incorrect, and that pkgutil.get_data() has the same security model as open(). The documentation has been updated to clarify this point. There is no vulnerability in the function if following the intended security model.
pkgutil.get_data() did not validate the resource argument as documented, allowing path traversals. |
| 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. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output(). |
| The "tarfile" module would still apply normalization of AREGTYPE (\x00) blocks to DIRTYPE, even while processing a multi-block member such as GNUTYPE_LONGNAME or GNUTYPE_LONGLINK. This could result in a crafted tar archive being misinterpreted by the tarfile module compared to other implementations. |
| 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. |
| User-controlled header names and values containing newlines can allow injecting HTTP headers. |
| When loading a plist file, the plistlib module reads data in size specified by the file itself, meaning a malicious file can cause OOM and DoS issues |
