BIT-python-min-2026-114583: tar filter allows writing outside destination via empty-named symlink
tarfile.tarfilter 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() with filter="tar" to write files outside the destination directory, subject to the permissions of the extracting process.
This is the tarfile.tarfilter counterpart of CVE-2026-7774, which covered tarfile.datafilter.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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bitnami/libpythonto a version that resolves this vulnerability.Fixed in 3.11.18 - Upgrade
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bitnami/libpythonto a version that resolves this vulnerability.Fixed in 3.12.16 - Upgrade
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bitnami/libpythonto a version that resolves this vulnerability.Fixed in 3.13.18 - Upgrade
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bitnami/libpythonto a version that resolves this vulnerability.Fixed in 3.14.10 - Upgrade
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bitnami/libpythonto a version that resolves this vulnerability.Fixed in 3.15.2 - Upgrade
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bitnami/pythonto a version that resolves this vulnerability.Fixed in 3.11.18 - Upgrade
Upgrade
bitnami/pythonto a version that resolves this vulnerability.Fixed in 3.12.16 - Upgrade
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bitnami/pythonto a version that resolves this vulnerability.Fixed in 3.13.18 - Upgrade
Upgrade
bitnami/pythonto a version that resolves this vulnerability.Fixed in 3.14.10 - Upgrade
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bitnami/pythonto a version that resolves this vulnerability.Fixed in 3.15.2 - Upgrade
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bitnami/python-minto a version that resolves this vulnerability.Fixed in 3.11.18 - Upgrade
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bitnami/python-minto a version that resolves this vulnerability.Fixed in 3.12.16 - Upgrade
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bitnami/python-minto a version that resolves this vulnerability.Fixed in 3.13.18 - Upgrade
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bitnami/python-minto a version that resolves this vulnerability.Fixed in 3.14.10 - Upgrade
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bitnami/python-minto a version that resolves this vulnerability.Fixed in 3.15.2
Event History
Frequently Asked Questions
Who is exposed to this issue?
Applications using tarfile.extractall() with filter="tar" on malicious or untrusted tar archives are exposed. The impact is limited by the permissions of the process performing extraction.
What does an attacker need to exploit it?
An attacker needs to provide a crafted tar archive containing link entries, such as symlinks with empty or directory-like names. No privileges or user interaction are indicated in the provided severity vector.
Are extra configuration changes required for exploitation?
The affected extraction path explicitly uses filter="tar". Exploitation occurs when that filter is used to extract the crafted archive; the provided data does not establish whether this is the default extraction configuration.
What can happen if exploitation succeeds?
Later archive members can be redirected and written outside the intended extraction directory. The attacker can write only where the extracting process has permission.