PSF-2010-1 rgbimg and imageop overflows

Buffer underflow in the rgbimg module in Python 2.5 allows remote attackers to cause a denial of service application crash via a large ZSIZE value in a black-and-white aka B/W RGB image that triggers an invalid pointer dereference...

PSF-2008-10 expandtab() integer overflow

Multiple integer overflows in Python 2.2.3 through 2.5.1, and 2.6, allow context-dependent attackers to have an unknown impact via a large integer value in the tabsize argument to the expandtabs method, as implemented by 1 the stringexpandtabs function in Objects/stringobject.c and 2 the...

PSF-2026-1

When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized...

PSF-2008-8 Multiple integer overflows (Apple)

Multiple integer overflows in the PyOSvsnprintf function in Python/mysnprintf.c in Python 2.5.2 and earlier allow context-dependent attackers to cause a denial of service memory corruption or have unspecified other impact via crafted input to string formatting operations. NOTE: the handling of...

PSF-2008-2 Multiple integer overflows (Apple)

Integer signedness error in the zlib extension module in Python 2.5.2 and earlier allows remote attackers to execute arbitrary code via a negative signed integer, which triggers insufficient memory allocation and a buffer overflow...

PSF-2025-11

There is a defect in the CPython “tarfile” module affecting the “TarFile” extraction and entry enumeration APIs. The tar implementation would process tar archives with negative offsets without error, resulting in an infinite loop and deadlock during the parsing of maliciously crafted tar archives...

PSF-2021-5 ftplib should not use the host from the PASV response

The IPv4 address value returned from the server in response to the PASV command should not be trusted. This prevents a malicious FTP server from using the response to probe IPv4 address and port combinations on the client network. Instead of using the returned address, we use the IP address we're...

PSF-2017-9 bpo-30500: urllib connects to a wrong host

The urllib module doesn't parse correctly password containing the character...

PSF-2016-4 Sweet32 attack (DES, 3DES)

The DES and Triple DES ciphers, as used in the TLS, SSH, and IPSec protocols and other protocols and products, have a birthday bound of approximately four billion blocks, which makes it easier for remote attackers to obtain cleartext data via a birthday attack against a long-duration encrypted...

PSF-2015-1 Issue #26556: Expat 2.1.1

Multiple integer overflows in the XMLGetBuffer function in Expat through 2.1.0, as used in Google Chrome before 44.0.2403.89 and other products, allow remote attackers to cause a denial of service heap-based buffer overflow or possibly have unspecified other impact via crafted XML data, a related...

PSF-2026-8

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 foldin...

PSF-2026-4

The poplib module, when passed a user-controlled command, can have additional commands injected using newlines. Mitigation rejects commands containing control characters...

PSF-2025-12

The 'zipfile' module would not check the validity of the ZIP64 End of Central Directory EOCD Locator record offset value would not be used to locate the ZIP64 EOCD record, instead the ZIP64 EOCD record would be assumed to be the previous record in the ZIP archive. This could be abused to create Z...

PSF-2025-7

Allows the extraction filter to be ignored, allowing symlink targets to point outside the destination directory, and the modification of some file metadata. You are affected by this vulnerability if using the tarfile module to extract untrusted tar archives using TarFile.extractall or...

PSF-2025-9

Allows arbitrary filesystem writes outside the extraction directory during extraction with filter="data". You are affected by this vulnerability if using the tarfile module to extract untrusted tar archives using TarFile.extractall or TarFile.extract using the filter= parameter with a value of...

PSF-2025-2

There is a defect in the CPython standard library module “mimetypes” where on Windows the default list of known file locations are writable meaning other users can create invalid files to cause MemoryError to be raised on Python runtime startup or have file extensions be interpreted as the...

PSF-2008-6 Multiple integer overflows (Apple)

Multiple buffer overflows in Python 2.5.2 and earlier on 32bit platforms allow context-dependent attackers to cause a denial of service crash or have unspecified other impact via a long string that leads to incorrect memory allocation during Unicode string processing, related to the unicoderesize...

PSF-2008-7 Multiple integer overflows (Google)

Multiple integer overflows in Python before 2.5.2 might allow context-dependent attackers to have an unknown impact via vectors related to 1 Include/pymem.h; 2 csv.c, 3 struct.c, 4 arraymodule.c, 5 audioop.c, 6 binascii.c, 7 cPickle.c, 8 cStringIO.c, 9 cjkcodecs/multibytecodec.c, 10...

PSF-2026-3

The imaplib module, when passed a user-controlled command, can have additional commands injected using newlines. Mitigation rejects commands containing control characters...

PSF-2026-2

User-controlled data URLs parsed by urllib.request.DataHandler allow injecting headers through newlines in the data URL mediatype...

PSF-2025-8

When using a TarFile.errorlevel = 0 and extracting with a filter the documented behavior is that any filtered members would be skipped and not extracted. However the actual behavior of TarFile.errorlevel = 0 in affected versions is that the member would still be extracted and not skipped...

PSF-2016-7 zipimporter overflow

Integer overflow in the getdata function in zipimport.c in CPython aka Python before 2.7.12, 3.x before 3.4.5, and 3.5.x before 3.5.2 allows remote attackers to have unspecified impact via a negative data size value, which triggers a heap-based buffer overflow...

PSF-2016-5 Windows: vulnerable bzip2 1.0.6

Use-after-free vulnerability in bzip2recover in bzip2 1.0.6 allows remote attackers to cause a denial of service crash via a crafted bzip2 file, related to block ends set to before the start of the block...

PSF-2014-3 zipfile DoS using invalid file size

Python before 3.3.4 RC1 allows remote attackers to cause a denial of service infinite loop and CPU consumption via a file size value larger than the size of the zip file to the 1 ZipExtFile.read, 2 ZipExtFile.readn, 3 ZipExtFile.readlines, 4 ZipFile.extract, or 5 ZipFile.extractall function...

PSF-2012-3 XML-RPC DoS

SimpleXMLRPCServer.py in SimpleXMLRPCServer in Python before 2.6.8, 2.7.x before 2.7.3, 3.x before 3.1.5, and 3.2.x before 3.2.3 allows remote attackers to cause a denial of service infinite loop and CPU consumption via an XML-RPC POST request that contains a smaller amount of data than specified...

PSF-2010-7 smtpd accept bug and race condition

Multiple race conditions in smtpd.py in the smtpd module in Python 2.6, 2.7, 3.1, and 3.2 alpha allow remote attackers to cause a denial of service daemon outage by establishing and then immediately closing a TCP connection, leading to the accept function having an unexpected return value of None...

PSF-2010-3 rgbimg and imageop overflows

Multiple buffer overflows in the RLE decoder in the rgbimg module in Python 2.5 allow remote attackers to have an unspecified impact via an image file containing crafted data that triggers improper processing within the 1 longimagedata or 2 expandrow function...

PSF-2008-9 Multiple integer overflows (Apple)

Multiple integer overflows in imageop.c in the imageop module in Python 1.5.2 through 2.5.1 allow context-dependent attackers to break out of the Python VM and execute arbitrary code via large integer values in certain arguments to the crop function, leading to a buffer overflow, a different...

PSF-2008-4 Multiple integer overflows (Apple)

Multiple integer overflows in Python 2.5.2 and earlier allow context-dependent attackers to have an unknown impact via vectors related to the 1 stringobject, 2 unicodeobject, 3 bufferobject, 4 longobject, 5 tupleobject, 6 stropmodule, 7 gcmodule, and 8 mmapmodule modules. NOTE: The expandtabs...

PSF-2025-16

When building nested elements using xml.dom.minidom methods such as appendChild that have a dependency on clearidcache the algorithm is quadratic. Availability can be impacted when building excessively nested documents...

PSF-2025-13

If the value passed to os.path.expandvars is user-controlled a performance degradation is possible when expanding environment variables...

PSF-2018-8 Email folding function Denial-of-Service

The email folding function enters an infinite loop if a header is longer than the policy maximum line length and contains many non-ASCII characters. Regression introduced in Python 3.6.4...

PSF-2016-1 ssl.match_hostname() IDNA issue

The ssl.matchhostname function in CPython aka Python before 2.7.9 and 3.x before 3.3.3 does not properly handle wildcards in hostnames, which might allow man-in-the-middle attackers to spoof servers via a crafted certificate...

PSF-2016-2 Expat 2.2 (Expat bug #537)

Expat allows context-dependent attackers to cause a denial of service crash or possibly execute arbitrary code via a malformed input document, which triggers a buffer overflow...

PSF-2012-5 Hash DoS

Python before 2.6.8, 2.7.x before 2.7.3, 3.x before 3.1.5, and 3.2.x before 3.2.3 computes hash values without restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service CPU consumption via crafted input to an application...

PSF-2012-6 Vulnerability in the utf-16 decoder after error handling

The utf-16 decoder in Python 3.1 through 3.3 does not update the alignedend variable after calling the unicodedecodecallerrorhandler function, which allows remote attackers to obtain sensitive information process memory or cause a denial of service memory corruption and crash via unspecified...

PSF-2008-3 Multiple integer overflows (Apple)

Python 2.5.2 and earlier allows context-dependent attackers to execute arbitrary code via multiple vectors that cause a negative size value to be provided to the PyStringFromStringAndSize function, which allocates less memory than expected when assert is disabled and triggers a buffer overflow...

PSF-2025-4

There is an issue in CPython when using bytes.decode"unicodeescape", error="ignore|replace". If you are not using the "unicodeescape" 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 ...

PSF-2010-5 audioop input validation

The audioop module in Python 2.7 and 3.2 does not verify the relationships between size arguments and byte string lengths, which allows context-dependent attackers to cause a denial of service memory corruption and application crash via crafted arguments, as demonstrated by a call to...

PSF-2008-1 Multiple integer overflows (Apple)

Multiple integer overflows in imageop.c in Python before 2.5.3 allow context-dependent attackers to cause a denial of service crash and possibly execute arbitrary code via crafted images that trigger heap-based buffer overflows. NOTE: this issue is due to an incomplete fix for CVE-2007-4965...

PSF-2026-44

ssl.SSLContext.wrapbio didn't require the serverhostname argument to not be None if ssl.SSLContext.checkhostname was set. Due to a missing parameter check in SSLObject, if the serverhostname argument isn't supplied then hostname verification would be silently skipped. This defect could lead to...

PSF-2026-43

A remote, unauthenticated TLS client can make a server crash or call through a freed pointer if its snicallback assigns a different context to SSLSocket.context the documented way to select a certificate per server name and nothing else keeps the original ssl.SSLContext alive. Typical cases are...

PSF-2025-10

The html.parser.HTMLParser class had worse-case quadratic complexity when processing certain crafted malformed inputs potentially leading to amplified denial-of-service...

PSF-2010-4 audioop integer overflows

Multiple integer overflows in audioop.c in the audioop module in Python 2.6, 2.7, 3.1, and 3.2 allow context-dependent attackers to cause a denial of service application crash via a large fragment, as demonstrated by a call to audioop.lin2lin with a long string in the first argument, leading to a...

PSF-2007-1 rgbimg and imageop overflows

Multiple integer overflows in the imageop module in Python 2.5.1 and earlier allow context-dependent attackers to cause a denial of service application crash and possibly obtain sensitive information memory contents via crafted arguments to 1 the tovideo method, and unspecified other vectors...

PSF-2025-14

When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS...

PSF-2016-9 Issue #26657: HTTP server directory traversal

Fix directory traversal vulnerability with http.server and SimpleHTTPServer on Windows. Regression of Python 3.3.5. Python issue reported at 2016-03-14...

PSF-2012-2 pypirc created insecurely

Python 2.6 through 3.2 creates /.pypirc with world-readable permissions before changing them after data has been written, which introduces a race condition that allows local users to obtain a username and password by reading this file...

PSF-2025-15

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...

PSF-2019-17 http.cookiejar: Incorrect validation of path

Cookies of example.com with path=/any were sent to example.com/anybad/ while using a cookiejar with http.cookiejar.DefaultCookiePolicy policy. The code did not check for the first non-matching character in prefix match to be a slash...