Cloudanix VulnDB

CVE-2026-114583

None

CVSS

—

EPSS

0.2%

Published

Oct 22, 2026

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A flaw in handling tar archives lets a specially made file slip extra content into places it should not reach during extraction, which could let attackers tamper with system files.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Low
Impact
Data Tampering
Component
Library
Class
Path Traversal
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Bypass of tarfile.tar_filter via crafted link entries (including symlinks with empty or directory-like names) that redirect subsequent archive members outside the extraction root, enabling writes beyond the intended directory when extractall(filter="tar") is used.

Why it matters to the business

Attackers can place files in arbitrary locations on systems that extract untrusted tar archives, potentially leading to configuration changes, code injection, or data corruption with minimal attacker effort.

How an attack unfolds

An attacker creates a malicious tar archive containing specially crafted link entries that exploit tar_filter logic gaps; when a victim application extracts the archive using extractall with the tar filter, files are written outside the destination directory subject only to the process permissions.

How to fix it

Upgrade to a Python version that corrects the tar_filter bypass; until then, avoid the tar filter, validate archive contents before extraction, or use data_filter with additional path checks.

How to confirm the fix worked

Confirm the installed Python version contains the tar_filter fix; test extraction of a crafted archive containing escaping link entries and verify all members remain inside the destination directory.

Typical attack path

  1. Craft tar archive with symlink entries using empty or dot-prefixed names to escape the target directory
  2. Deliver the archive to a target that calls tarfile.extractall(filter="tar") on untrusted input
  3. Trigger extraction so later members are written to attacker-chosen paths
  4. Execute or load the written files to achieve persistence or further compromise

How to detect it

Review application logs for tarfile extraction calls on externally supplied archives; inspect extracted file timestamps and paths for entries that appear outside expected directories; correlate with process creation events following archive handling.

What your security team should do

  • Apply the upstream Python patch for tarfile.tar_filter immediately given the four-day publication window
  • Audit code that extracts tar archives from untrusted sources and replace use of the tar filter
  • Add runtime checks or sandboxing around tar extraction operations
  • Monitor EPSS and threat feeds for any rise in exploitation activity

The record

tarfile.tar_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() with filter="tar" to write files outside the destination directory, subject to the permissions of the extracting process. This is the tarfile.tar_filter counterpart of CVE-2026-7774, which covered tarfile.data_filter.

Affected packages

Ecosystem Package Introduced Fixed