gh-149486: tarfile.data_filter: validate written link target#149487
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encukou wants to merge 3 commits intopython:mainfrom
Open
gh-149486: tarfile.data_filter: validate written link target#149487encukou wants to merge 3 commits intopython:mainfrom
encukou wants to merge 3 commits intopython:mainfrom
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The data filter rewrote linknames with normpath() but ran the containment check against the un-normalised value, and computed a symlink's directory before stripping trailing slashes. Both let a crafted archive create links pointing outside the destination. Also reject link members that resolve to the destination directory itself, which could otherwise replace it with a symlink and redirect all subsequent members.
encukou
added
needs backport to 3.12
gpshead
approved these changes
May 7, 2026
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