Release date:
2026-09-24 01:08:09 UTC
Description:
* SECURITY UPDATE: tarfile 'data'/'tar' extraction filter bypass via a hard
link to a symbolic link (CWE-59, link following). TarFile.makelink_with_filter()
passed tarinfo._link_target straight to os.link(); link(2) does not follow
symbolic links, so an archive storing a hard link whose target is an
archived symlink got the *same symlink inode* materialised one directory
shallower than the symlink the filter had validated. Its relative body then
re-based outside the destination directory, and the chmod()/utime() that
extraction performs on the newly created name followed the link onto the
outside file, changing its permissions and modification time; its contents
also became readable through the in-tree path. Reproduced on the patched
3.9.23 tree with a four-member archive ('x' regular decoy, 'sub/'
directory, 'sub/link' -> '../x' symlink, 'escape' hard link to 'sub/link'
with mode 0777 and mtime 946684800) extracted with filter='data': a file
outside the destination went 0600 -> 0755, its mtime was rewritten to
946684800 and its contents were readable through dest/escape. After the
fix the outside file is untouched and dest/escape is a genuine in-tree hard
link to the extracted decoy.
- debian/patches/CVE-2026-82049.patch: backport of cpython
b8f23e307097552eaea2604383a12ab280520d0d (gh-157190, GH-157191,
GH-157192), which resolves the hard-link source with os.path.realpath()
before calling os.link(), plus its regression test
test_sneaky_hardlink_relocation in Lib/test/test_tarfile.py. This
one-liner is sufficient only because CVE-2026-11940 is already applied:
it closes the variant where the archive carries a decoy at the symlink's
in-destination target so os.path.exists() is true and os.link() runs,
while the no-decoy variant skips os.link() entirely and is closed by the
guard CVE-2026-11940.patch added to makelink_with_filter(). The two must
not be separated.
- CVE-2026-82049
Updated packages:
-
alt-python39_3.9.23-30_amd64.deb
sha:fdf9aa525bbaa9a209edf567167c0208d630a07c
-
alt-python39-debug_3.9.23-30_amd64.deb
sha:776ea692c0a018f87e1139973bc66055114ab6cb
-
alt-python39-devel_3.9.23-30_amd64.deb
sha:a50974ecb4e43e70112c7a4b875577b65e662fa3
-
alt-python39-idle_3.9.23-30_amd64.deb
sha:381834b635f78bf0d6fca89f8bebcd0dd6da80dc
-
alt-python39-libs_3.9.23-30_amd64.deb
sha:bdef65275d389950031059a515a15e4de3aaba03
-
alt-python39-test_3.9.23-30_amd64.deb
sha:1abde7d74b89d7b8a060b0a519df20ff7ece9d84
-
alt-python39-tkinter_3.9.23-30_amd64.deb
sha:48f7220833a8a090461f90fed3543b6e394be74d
-
alt-python39_3.9.23-30_arm64.deb
sha:7139d5558403ec438e15ce31449b97c05dec8409
-
alt-python39-debug_3.9.23-30_arm64.deb
sha:df45ae05b05c2e4db3fda8269e8757c722a51941
-
alt-python39-devel_3.9.23-30_arm64.deb
sha:e19bbfb757d940397ccb44bb94d2d1b534a74b0c
-
alt-python39-idle_3.9.23-30_arm64.deb
sha:3ca04113fe39a0a8af3e334dfb695ad68b3a937f
-
alt-python39-libs_3.9.23-30_arm64.deb
sha:40389b33e9fe4ba22b23baa062d0a463c6c32118
-
alt-python39-test_3.9.23-30_arm64.deb
sha:edc8d3593c3c3aa3230321e6cb0b678f4dc0896a
-
alt-python39-tkinter_3.9.23-30_arm64.deb
sha:0f9d94fb3b0b5da7702ea78a287bca506152cb65
Notes:
This page is generated automatically and has not been checked for errors. For clarification or
corrections please contact the
CloudLinux Packaging Team.