# CVE-2026-11972: tarfile opened in streaming mode mishandles EOF > Attackers can cause excessive CPU consumption and service unavailability by exploiting improper EOF handling in Python's tarfile streaming mode. - **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 23 Jun 2026 - **Updated:** 13 Aug 2026 - **Also known as:** ALPINE-CVE-2026-11972, AZL-91248, BELL-CVE-2026-11972, BIT-libpython-2026-11972, BIT-python-2026-11972, BIT-python-min-2026-11972, CLSA-2026-1785455842, CLSA-2026-1785456223, CLSA-2026-1785457027, CLSA-2026-1785515860, CLSA-2026-1785844339, CLSA-2026-1786091187, CLSA-2026-1786093153, CLSA-2026-1786223340, CLSA-2026-1786609534, CLSA-2026-1789605854, CLSA-2026-1789723233, DEBIAN-CVE-2026-11972, ECHO-e70a-36e0-4574, GHSA-wqxf-pjxh-hh4h, MINI-676m-c38g-fj5m, MINI-86xp-vj3x-jwxc, MINI-8h78-3x65-hrx6, MINI-c87x-wm86-rrwm, MINI-jj72-86qc-8w5p, PSF-2026-31, RHSA-2026:35806, RHSA-2026:35807, RHSA-2026:35812, RHSA-2026:35813, ROOT-OS-ALPINE-320-CVE-2026-11972, ROOT-OS-DEBIAN-11-CVE-2026-11972, ROOT-OS-DEBIAN-12-CVE-2026-11972, ROOT-OS-DEBIAN-13-CVE-2026-11972, UBUNTU-CVE-2026-11972 ## What is CVE-2026-11972? CVE-2026-11972 is a high-severity denial of service vulnerability in CPython, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description 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. Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-606 (Unchecked Input for Loop Condition), CWE-252 (Unchecked Return Value) ## Which versions are affected by CVE-2026-11972? 3 open source packages ship an affected version, including libpython, python and python-min. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `libpython` | Bitnami | All versions | 3.10.21, 3.11.16, 3.12.14, 3.13.15, 3.14.7 | | `python` | Bitnami | All versions | 3.10.21, 3.11.16, 3.12.14, 3.13.15, 3.14.7 | | `python-min` | Bitnami | All versions | 3.10.21, 3.11.16, 3.12.14, 3.13.15, 3.14.7 | | `python3.11` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.4.hum1 | | `python3.11-debug` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.4.hum1 | | `python3.11-devel` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.4.hum1 | | `python3.11-idle` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.4.hum1 | | `python3.11-libs` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.4.hum1 | | `python3.11-test` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.4.hum1 | | `python3.11-tkinter` | Red Hat:hummingbird:1 | All versions | 0:3.11.15-4.4.hum1 | | `python3.12` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.3.hum1 | | `python3.12-debug` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.3.hum1 | | `python3.12-devel` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.3.hum1 | | `python3.12-idle` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.3.hum1 | | `python3.12-libs` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.3.hum1 | | `python3.12-test` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.3.hum1 | | `python3.12-tkinter` | Red Hat:hummingbird:1 | All versions | 0:3.12.13-3.3.hum1 | | `python3.13` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.2.hum1 | | `python3.13-debug` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.2.hum1 | | `python3.13-devel` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.2.hum1 | | `python3.13-freethreading` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.2.hum1 | | `python3.13-freethreading-debug` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.2.hum1 | | `python3.13-idle` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.2.hum1 | | `python3.13-libs` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.2.hum1 | | `python3.13-test` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.2.hum1 | | `python3.13-tkinter` | Red Hat:hummingbird:1 | All versions | 0:3.13.14-1.2.hum1 | | `python3.14` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-debug` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-devel` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-freethreading` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-freethreading-debug` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-freethreading-devel` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-freethreading-idle` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-freethreading-libs` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-freethreading-test` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-freethreading-tkinter` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-idle` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-libs` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-test` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | | `python3.14-tkinter` | Red Hat:hummingbird:1 | All versions | 0:3.14.6-1.2.hum1 | ## How do I fix CVE-2026-11972? Upgrade libpython to a fixed version for your release line: 3.10.21, 3.11.16, 3.12.14 or 3.13.15. ## Is CVE-2026-11972 being exploited? There is no known exploitation of CVE-2026-11972 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-11972 and fix it if it is affected. What it is: CVE-2026-11972 is a high-severity denial of service vulnerability in CPython, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-11972 in the wild and no public exploit code. Affected packages and fixed versions: - libpython (Bitnami): affected all versions; fixed in 3.10.21, 3.11.16, 3.12.14, 3.13.15, 3.14.7 - python (Bitnami): affected all versions; fixed in 3.10.21, 3.11.16, 3.12.14, 3.13.15, 3.14.7 - python-min (Bitnami): affected all versions; fixed in 3.10.21, 3.11.16, 3.12.14, 3.13.15, 3.14.7 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-11972/ (Markdown: https://insights.sbomify.com/CVE-2026-11972/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11972 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11972 - OSV: https://osv.dev/vulnerability/CVE-2026-11972 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-11972/ Summaries are generated and may contain mistakes; the official description above is the record.