CVE-2026-9669

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.

Python combines remarkable power with very clear syntax. It has modules, classes, exceptions, very high level dynamic data types, and dynamic typing. There are interfaces to many system calls and libraries, as well as to various windowing systems. New built-in modules are easily written in C or C++ (or other languages, depending on the chosen implementation). Python is also usable as an extension language for applications written in other languages that need easy-to-use scripting or automation interfaces.

Security Fix(es):

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.(CVE-2026-7774)

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.(CVE-2026-9669)

Python combines remarkable power with very clear syntax. It has modules, classes, exceptions, very high level dynamic data types, and dynamic typing. There are interfaces to many system calls and libraries, as well as to various windowing systems. New built-in modules are easily written in C or C++ (or other languages, depending on the chosen implementation). Python is also usable as an extension language for applications written in other languages that need easy-to-use scripting or automation interfaces.

Security Fix(es):

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.(CVE-2026-7774)

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.(CVE-2026-9669)

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.

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.

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.

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.

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.

• SECURITY UPDATE: out-of-bounds stack write when a bz2 decompressor or BZ2File handle is reused after a decompression error
  • debian/patches/CVE-2026-9669.patch: record the bzlib error code on BZ2DecompObject and refuse further decompress() calls with ValueError in Modules/bz2module.c, so that crafted input can no longer make BZ2_bzDecompress() resume from an invalid internal state; also make the error sticky for the C BZ2File read paths, which re-entered the errored stream in the same way, and add regression tests for both
  • CVE-2026-9669

• SECURITY UPDATE: out-of-bounds write on bz2 decompressor and BZ2File reuse after a decompression error
  • debian/patches/CVE-2026-9669.patch: make a libbz2 decompression error sticky on the decompressor object and on the BZ2File read paths in Modules/bz2module.c, so a reused object can no longer re-enter BZ2_bzDecompress() on an errored stream and write out of bounds
  • CVE-2026-9669

• CVE-2026-9669: fix a possible stack buffer overflow in bz2 by making a BZ2Decompressor unusable after libbz2 reports a decompression error

• CVE-2026-9669: fix a possible stack buffer overflow in bz2 by making a BZ2Decompressor unusable after libbz2 reports a decompression error

• SECURITY UPDATE: quadratic parse time in the tarfile module when a streaming archive declares an offset past the end of the stream
  • debian/patches/CVE-2026-11972.patch: stop the forward-seek loop in _Stream.seek() as soon as read() returns no data, in Lib/tarfile.py, so a crafted mode="r|" archive can no longer keep the parser reading an exhausted stream.
  • CVE-2026-11972
• SECURITY UPDATE: out-of-bounds write when a bz2 decompressor is reused after a decompression error
  • debian/patches/CVE-2026-9669.patch: record the libbzip2 error in the BZ2Decompressor object and refuse any further decompress() call with ValueError, in Modules/_bz2module.c, so retrying with the same object can no longer re-enter BZ2_bzDecompress() on a bz_stream left in an invalid internal state.
  • CVE-2026-9669

• SECURITY UPDATE: quadratic parse time in the tarfile module when a streaming archive declares an offset past the end of the stream
  • debian/patches/CVE-2026-11972.patch: stop the forward-seek loop in _Stream.seek() as soon as read() returns no data, in Lib/tarfile.py, so a crafted mode="r|" archive can no longer keep the parser reading an exhausted stream.
  • CVE-2026-11972
• SECURITY UPDATE: out-of-bounds write when a bz2 decompressor is reused after a decompression error
  • debian/patches/CVE-2026-9669.patch: record the libbzip2 error in the BZ2Decompressor object and refuse any further decompress() call with ValueError, in Modules/_bz2module.c, so retrying with the same object can no longer re-enter BZ2_bzDecompress() on a bz_stream left in an invalid internal state.
  • CVE-2026-9669

• CVE-2026-9669: fix a possible stack buffer overflow in bz2 by making a BZ2Decompressor unusable after libbz2 reports a decompression error

• CVE-2026-9669: fix a stack buffer overflow in the bz2 module when a BZ2Decompressor object is reused after a decompression error; the decompressor now becomes unusable once libbz2 reports an error, instead of resuming from an invalid internal state

• CVE-2026-9669: fix a stack buffer overflow in the bz2 module when a BZ2Decompressor object is reused after a decompression error; the decompressor now becomes unusable once libbz2 reports an error, instead of resuming from an invalid internal state

• CVE-2026-87910: tarfile: skip a link member when the extraction filter returns None for its hardlink-extraction fallback instead of ignoring the filter result
• CVE-2026-17084: stringprep: build the RFC 3454 B.2/B.3 tables from Unicode 3.2.0 data so IDNA 2003 encoding of newly case-folding characters no longer depends on the interpreter's Unicode version
• CVE-2026-15310: zipfile: bound the output of each bzip2/LZMA decompress() call so a small crafted member cannot trigger an unbounded allocation
• CVE-2026-9669: bz2: refuse to reuse a BZ2Decompressor after a decompression error, so retrying with the same object can no longer resume from an invalid internal state and write out of bounds
• CVE-2026-11972: tarfile: stop the streaming-mode seek() loop at EOF so a member header declaring a huge size no longer makes parsing take exponentially longer

• CVE-2026-11972: stop tarfile._Stream.seek() looping over the declared block count once the stream is at EOF, so a crafted header advertising a huge member size can no longer make a streaming-mode read take exponentially longer
• CVE-2026-9669: latch the libbz2 error in BZ2Decompressor and refuse further use with ValueError, so an application that retries a decompressor after an OSError can no longer re-enter BZ2_bzDecompress() on invalid internal state and drive out-of-bounds writes to a stack buffer

• CVE-2026-9669: latch the libbz2 error in BZ2Decompressor and raise ValueError from any further decompress(), so a decompressor that has already failed can no longer be reused

• SECURITY UPDATE: out-of-bounds write via bz2 stream reuse after a decompression error (CVE-2026-9669)
  • debian/patches/CVE-2026-9669.patch: record the libbz2 error code on the BZ2Decompressor and BZ2File objects in Modules/bz2module.c and refuse every later decompress() or read() call, so BZ2_bzDecompress() is never re-entered on a stream libbz2 has already reported an error for; adds regression tests for both paths to Lib/test/test_bz2.py
  • CVE-2026-9669

• SECURITY UPDATE: CPU denial-of-service in tarfile streaming mode via a crafted archive that declares more blocks than it contains
  • debian/patches/CVE-2026-11972.patch: in Lib/tarfile.py, break out of the block loop in _Stream.seek() once read() returns no data, so an archive opened in streaming mode (mode='r|') can no longer make parsing take exponentially longer by declaring a block count past end of file. Backport of upstream commit 3f031d431f80 (gh-151981 / GH-151982), taken unchanged from this package's amazonlinux2els branch where it was adapted for 3.7 by Qiantong Zhong [email protected]. Bundles the upstream regression test test_getmembers_big_size (test_tarfile.py).
  • CVE-2026-11972
• SECURITY UPDATE: out-of-bounds stack write when a bz2 decompressor is reused after a decompression error
  • debian/patches/CVE-2026-9669.patch: in Modules/_bz2module.c, record the libbz2 error code on BZ2Decompressor and raise ValueError on any further decompress() call, so an application that catches the OSError and retries with the same decompressor can no longer make it resume from an invalid internal state and write out of bounds to a stack buffer. Backport of upstream commit 938ec030e90c (gh-150599 / GH-150600) via the 3.10 backport; self->bzerror = 0; is placed by hand in _bz2_BZ2Decompressor___init___impl(), whose lock-allocation prologue differs in this version. Bundles the upstream regression test test_decompress_after_data_error (test_bz2.py).
  • CVE-2026-9669

• CVE-2026-11972: break out of the block loop in tarfile._Stream.seek as soon as read() returns no data, so a member header declaring a huge size can no longer keep a stream-mode archive spinning until it is interrupted
• CVE-2026-9669: latch the libbz2 error code in BZ2Decomp_decompress and raise ValueError on any later call, so a BZ2Decompressor cannot be re-entered after a decompression error and write outside its output buffer; the same error is latched on BZ2FileObject through the new Util_BzRead wrapper, so a BZ2File whose stream already errored re-reports that IOError on every later read instead of re-entering BZ2_bzDecompress

• CVE-2026-11972: break out of the block loop in tarfile._Stream.seek as soon as read() returns no data, so a member header declaring a huge size can no longer keep a stream-mode archive spinning until it is interrupted
• CVE-2026-9669: latch the libbz2 error code in BZ2Decomp_decompress and raise ValueError on any later call, so a BZ2Decompressor cannot be re-entered after a decompression error and write outside its output buffer; the same error is latched on BZ2FileObject through the new Util_BzRead wrapper, so a BZ2File whose stream already errored re-reports that IOError on every later read instead of re-entering BZ2_bzDecompress

• CVE-2026-87910: tarfile: skip a link member when the extraction filter returns None for its hardlink-extraction fallback instead of ignoring the filter result
• CVE-2026-17084: stringprep: build the RFC 3454 B.2/B.3 tables from Unicode 3.2.0 data so IDNA 2003 encoding of newly case-folding characters no longer depends on the interpreter's Unicode version
• CVE-2026-15310: zipfile: bound the output of each bzip2/LZMA decompress() call so a small crafted member cannot trigger an unbounded allocation
• CVE-2026-9669: bz2: refuse to reuse a BZ2Decompressor after a decompression error, so retrying with the same object can no longer resume from an invalid internal state and write out of bounds

• CVE-2026-87910: tarfile: skip a link member when the extraction filter returns None for its hardlink-extraction fallback instead of ignoring the filter result
• CVE-2026-17084: stringprep: build the RFC 3454 B.2/B.3 tables from Unicode 3.2.0 data so IDNA 2003 encoding of newly case-folding characters no longer depends on the interpreter's Unicode version
• CVE-2026-15310: zipfile: bound the output of each bzip2/LZMA decompress() call so a small crafted member cannot trigger an unbounded allocation
• CVE-2026-9669: bz2: refuse to reuse a BZ2Decompressor after a decompression error, so retrying with the same object can no longer resume from an invalid internal state and write out of bounds

• CVE-2026-87910: tarfile: skip a link member when the extraction filter returns None for its hardlink-extraction fallback instead of ignoring the filter result
• CVE-2026-17084: stringprep: build the RFC 3454 B.2/B.3 tables from Unicode 3.2.0 data so IDNA 2003 encoding of newly case-folding characters no longer depends on the interpreter's Unicode version
• CVE-2026-15310: zipfile: bound the output of each bzip2/LZMA decompress() call so a small crafted member cannot trigger an unbounded allocation
• CVE-2026-9669: bz2: refuse to reuse a BZ2Decompressor after a decompression error, so retrying with the same object can no longer resume from an invalid internal state and write out of bounds

• SECURITY UPDATE: CPU denial of service via unbounded block skipping past end of stream in tarfile
  • debian/patches/CVE-2026-11972.patch: break out of the block skipping loop in _Stream.seek() as soon as read() returns no data in Lib/tarfile.py, so an attacker declared member size can no longer make parsing a stream mode ("r|") archive take exponentially longer; add regression test to Lib/test/test_tarfile.py
  • CVE-2026-11972
• SECURITY UPDATE: Out-of-bounds write when a bz2 decompressor or a BZ2File handle is reused after a decompression error
  • debian/patches/CVE-2026-9669.patch: record the failing libbz2 error code on BZ2DecompObject and refuse any further decompress() call with ValueError in Modules/bz2module.c, so crafted input can no longer make BZ2_bzDecompress() resume from an invalid internal state and write out of bounds to a stack buffer; also make the error sticky for the C BZ2File read paths, which re-entered the errored stream in the same way; add regression tests for both to Lib/test/test_bz2.py
  • CVE-2026-9669

• CVE-2026-11972: break out of the block loop in tarfile._Stream.seek as soon as read() returns no data, so a member header declaring a huge size can no longer keep a stream-mode archive spinning until it is interrupted
• CVE-2026-9669: latch the libbz2 error code in BZ2Decomp_decompress and raise ValueError on any later call, so a BZ2Decompressor cannot be re-entered after a decompression error and write outside its output buffer; the same error is latched on BZ2FileObject through the new Util_BzRead wrapper, so a BZ2File whose stream already errored re-reports that IOError on every later read instead of re-entering BZ2_bzDecompress

These are all security issues fixed in the python314-3.14.6-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python310-3.10.21-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python315-3.15.0~rc2-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python311-3.11.16-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python312-3.12.14-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python313-3.13.15-1.1 package on the GA media of openSUSE Tumbleweed.

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.

Root has patched CVE-2026-9669 in the python3 package for Root:Alpine:3.20. Multiple fixed versions available.

Root has patched CVE-2026-9669 in the python3.9 package for Root:Debian:11. Multiple fixed versions available.

Root has patched CVE-2026-9669 in the python3.11 package for Root:Debian:12. Multiple fixed versions available.

This update for python311 fixes the following issues:

• CVE-2025-13462: incorrect parsing of TarInfo header when GNU long name and type AREGTYPE are combined (bsc#1259611).
• CVE-2026-0864: improper handling of line-ending characters can lead to configuration file injection when the configparser module is used (bsc#1269066).
• CVE-2026-1502: HTTP client proxy tunnel headers not validated for CR/LF (bsc#1261969).
• CVE-2026-2297: cpython: incorrectly handled hook in FileLoader can lead to validation bypass (bsc#1259240).
• CVE-2026-3276: quadratic complexity in unicodedata.normalize() can lead to DoS when processing specially crafted Unicode input (bsc#1267581).
• CVE-2026-3644: incomplete control character validation in http.cookies (bsc#1259734).
• CVE-2026-4224: C stack overflow when parsing XML with deeply nested DTD content models (bsc#1259735).
• CVE-2026-4360: in the Tarfile.extract() function, the filter parameter is not passed properly when extracting hardlinks (bsc#1269959).
• CVE-2026-4519: leading dashes in URLs are accepted by the webbrowser.open() API and allow for web browser command line option injection (bsc#1260026).
• CVE-2026-4786: Incomplete mitigation of %action expansion for command injection to webbrowser.open() (bsc#1262319).
• CVE-2026-6100: Arbitrary code execution or information disclosure via use-after-free in decompression modules (bsc#1262098).
• CVE-2026-7210: xml.parsers.expat and xml.etree.ElementTree use insufficient entropy for Expat hash-flooding protection (bsc#1264962).
• CVE-2026-7774: tarfile.data_filter path traversal bypass allows writing outside the extraction directory (bsc#1267821).
• CVE-2026-8328: ftpcp() does not use actual peer address and trusts server-supplied PASV host address (bsc#1265268).
• CVE-2026-9669: crafted input can cause a stack buffer overflow (bsc#1267974).
• CVE-2026-11940: tarfile extraction filter bypass via a crafted archive allows escaping the destination directory and enables arbitrary file reads and writes (bsc#1268977).
• CVE-2026-11972: infinite loop due to improper EOF handling in the tarfile module streaming mode can lead to DoS (bsc#1269788).
• CVE-2026-15308: Incremental HTMLParser allows CPU-exhaustion DoS via repeated unterminated markup declarations (bsc#1271192).
• CVE-2026-15806: urllib.request.HTTPPasswordMgr credentials for one URL scheme sent over another scheme (bsc#1276223).
• CVE-2026-17084: StringPrep algorithm considered Unicode codepoint attributes outside Unicode 3.2.0 (bsc#1276226).

Changes for python311:

• Update to 3.11.16:
• Build
• gh-153438: Update Windows build and installer tooling and documentation to use the current download URL for nuget.exe.
• Library
• gh-109638: Fix exponential time in csv.Sniffer.sniff() for a sample which contains many quote characters. A doubled quote character is now also detected in a field which contains the delimiter or a line break.
• gh-98820: Fix quadratic time in csv.Sniffer.sniff() for a sample which contains quoted fields, in particular for a single column of quoted fields.
• gh-149231: In tomllib, the number of parts in TOML keys is now limited.
• gh-146083: Update bundled libexpat to version 2.7.5.
• gh-141707: Don't change tarfile.TarInfo type from AREGTYPE to DIRTYPE when parsing GNU long name or link headers (bsc#1259611, CVE-2025-13462).
• gh-90949: Add SetBillionLaughsAttackProtectionActivationThreshold() and SetBillionLaughsAttackProtectionMaximumAmplification() to xmlparser objects to tune protections against billion laughs attacks. Patch by B�n�dikt Tran.
• gh-100372: ssl.SSLContext.load_verify_locations() no longer incorrectly accepts some cases of trailing data when parsing DER.
• Security
• gh-155558: Update bundled libexpat to version 2.8.3 for the fix to CVE-2026-72522.
• gh-153030: Fixed quadratic complexity in incremental parsing of long unterminated constructs (such as tags or comments) in…

This update for python311 fixes the following issues:

• CVE-2026-9669: crafted input can cause a stack buffer overflow (bsc#1267974).
• CVE-2026-15806: urllib.request.HTTPPasswordMgr credentials for one URL scheme sent over another scheme (bsc#1276223).
• CVE-2026-17084: StringPrep algorithm considered Unicode codepoint attributes outside Unicode 3.2.0 (bsc#1276226).

Changes for python311:

• Updated to version 3.11.16

This update for python311 fixes the following issues:

• CVE-2026-9669: crafted input can cause a stack buffer overflow (bsc#1267974).
• CVE-2026-15310: memory exhaustion in zipfile in bzip2/LZMA/Zstandard decompression (bsc#1277111).
• CVE-2026-15806: urllib.request.HTTPPasswordMgr credentials for one URL scheme sent over another scheme (bsc#1276223).
• CVE-2026-17084: StringPrep algorithm considered Unicode codepoint attributes outside Unicode 3.2.0 (bsc#1276226).
• CVE-2026-19672: The tarfile module's tar and data extraction filters created directories outside the destination for members whose name leaves the destination and retu (bsc#1276227).

Changes for python311:

• Update to version 3.11.16.