---
id: CVE-2026-11972
title: >-
  When using the "tarfile" module with a file opened in "streaming mode"
  (mode="r|") the tarfile module did not properly handle EOF, making archive
  parsing take exponentially longer.
summary: >-
  When using the "tarfile" module with a file opened in "streaming mode"
  (mode="r|") the tarfile module did not properly handle EOF, making archive
  parsing take exponentially longer.
severity: none
cwe:
  - CWE-252
  - CWE-606
  - CWE-770
published: '2026-06-23'
updated: '2026-08-06'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-11972'
references:
  - url: >-
      https://github.com/python/cpython/commit/3f031d431f80668e14f3bc066bbf4369cd9281b9
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/4ce6bf7c8aa7725828a38981c306f214c1f29365
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/7f0dc59c9a70f8f3b4da33d7c4a2ba552a7acc21
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/e86666c9dd256d52d0fbef6feb1ea4a51768fdec
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/eb63c0f94dfcbea7fda8eab6213818e134d67192
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/f50bf13566189c8d0ce5a814f33eff3d89951896
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/f5e2776ff0383a902c12acf2b703e7e951fc8438
    label: cna@python.org
  - url: 'https://github.com/python/cpython/issues/151981'
    label: cna@python.org
  - url: 'https://github.com/python/cpython/pull/151982'
    label: cna@python.org
  - url: >-
      https://mail.python.org/archives/list/security-announce@python.org/thread/AXPSKKTSRKXTTJULW3XSIC74WZNAAPPB/
    label: cna@python.org
tags:
  - nvd
epss: 0.00445
epssPercentile: 0.38093
ingestedAt: '2026-08-06T20:03:56.259Z'
---

## Overview

When using the "tarfile" module with a file opened in "streaming mode" (mode="r|") the tarfile module did not properly handle EOF, making archive parsing take exponentially longer.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.