BIT-libpython-2026-114583: tar filter allows writing outside destination via empty-named symlink

Published Oct 22, 2026

Updated

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

18 affected componentsFixes available

bitnami/libpython<3.11.18

3.11.18

bitnami/libpython>=3.12.0<3.12.16

3.12.16

bitnami/libpython>=3.13.0<3.13.18

3.13.18

bitnami/libpython>=3.14.0<3.14.10

3.14.10

bitnami/libpython>=3.15.0<3.15.2

3.15.2

bitnami/libpython>=3.16.0

bitnami/python<3.11.18

3.11.18

bitnami/python>=3.12.0<3.12.16

3.12.16

bitnami/python>=3.13.0<3.13.18

3.13.18

bitnami/python>=3.14.0<3.14.10

3.14.10

bitnami/python>=3.15.0<3.15.2

3.15.2

bitnami/python>=3.16.0

bitnami/python-min<3.11.18

3.11.18

bitnami/python-min>=3.12.0<3.12.16

3.12.16

bitnami/python-min>=3.13.0<3.13.18

3.13.18

bitnami/python-min>=3.14.0<3.14.10

3.14.10

bitnami/python-min>=3.15.0<3.15.2

3.15.2

bitnami/python-min>=3.16.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade bitnami/libpython to a version that resolves this vulnerability.
Fixed in 3.11.18
Upgrade
Upgrade bitnami/libpython to a version that resolves this vulnerability.
Fixed in 3.12.16
Upgrade
Upgrade bitnami/libpython to a version that resolves this vulnerability.
Fixed in 3.13.18
Upgrade
Upgrade bitnami/libpython to a version that resolves this vulnerability.
Fixed in 3.14.10
Upgrade
Upgrade bitnami/libpython to a version that resolves this vulnerability.
Fixed in 3.15.2
Upgrade
Upgrade bitnami/python to a version that resolves this vulnerability.
Fixed in 3.11.18
Upgrade
Upgrade bitnami/python to a version that resolves this vulnerability.
Fixed in 3.12.16
Upgrade
Upgrade bitnami/python to a version that resolves this vulnerability.
Fixed in 3.13.18
Upgrade
Upgrade bitnami/python to a version that resolves this vulnerability.
Fixed in 3.14.10
Upgrade
Upgrade bitnami/python to a version that resolves this vulnerability.
Fixed in 3.15.2
Upgrade
Upgrade bitnami/python-min to a version that resolves this vulnerability.
Fixed in 3.11.18
Upgrade
Upgrade bitnami/python-min to a version that resolves this vulnerability.
Fixed in 3.12.16
Upgrade
Upgrade bitnami/python-min to a version that resolves this vulnerability.
Fixed in 3.13.18
Upgrade
Upgrade bitnami/python-min to a version that resolves this vulnerability.
Fixed in 3.14.10
Upgrade
Upgrade bitnami/python-min to a version that resolves this vulnerability.
Fixed in 3.15.2

Event History

Oct 22, 2026

CVE Published

via OSV·08:57 PM

Advisory Published

via OSV·08:57 PM

Data Sourced

via OSV·08:57 PM

DescriptionSeverity

Oct 29, 2026

Data Sourced

via OSV·12:12 PM

Affected Software

Frequently Asked Questions

Who is exposed to this issue?

Applications using tarfile.extractall() with filter="tar" on attacker-controlled or otherwise untrusted tar archives are exposed. The impact is limited by the filesystem 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. Later archive members can then be redirected to locations outside the intended extraction directory.

Does use of the tar filter prevent this attack?

No. The issue is specifically a bypass of tarfile.tar_filter, so extraction with filter="tar" can still write outside the destination directory when processing a crafted archive.

How can I identify potentially affected usage?

Review code and services that call tarfile.extractall() with filter="tar", especially where archives originate from uploads, downloads, build inputs, or other untrusted sources. Check whether the extracting process has permissions to write to sensitive paths outside the extraction destination.

BIT-libpython-2026-114583: tar filter allows writing outside destination via empty-named symlink

Affected Software

Remediation

Event History

Frequently Asked Questions

Who is exposed to this issue?

What does an attacker need to exploit it?

Does use of the tar filter prevent this attack?

How can I identify potentially affected usage?

Company

Resources

Contact

Frequently Asked Questions

Who is exposed to this issue?

What does an attacker need to exploit it?

Does use of the tar filter prevent this attack?

How can I identify potentially affected usage?