MediumCVE-2026-114583

    tar filter allows writing outside destination via empty-named symlink (CVE-2026-114583)

    Published Last modified Sources: BSI, OSV, Msrc Update Guide, CVE.org, HKCERT

    What is affected, what to do

    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.

    Update Python Software Foundation CPython to version 3.11.18, Python Software Foundation CPython to version 3.12.16, Python Software Foundation CPython to version 3.13.18.

    Affected
    • Python Software Foundation CPython lt *..3.11.18
    • Python Software Foundation CPython lt 3.12.0..3.12.16
    • Python Software Foundation CPython lt 3.13.0..3.13.18
    • Python Software Foundation CPython lt 3.14.0..3.14.10
    • Python Software Foundation CPython lt 3.15.0..3.15.2
    • Python Software Foundation CPython lt 3.16.0a1..3.16.0
    Fixed in
    • Python Software Foundation CPython 3.11.18
    • Python Software Foundation CPython 3.12.16
    • Python Software Foundation CPython 3.13.18
    • Python Software Foundation CPython 3.14.10
    • Python Software Foundation CPython 3.15.2
    • Python Software Foundation CPython 3.16.0

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    6.9

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v4

    6.9

    CVSS v4

    Severity Medium on the scale from 0 to 10.

    Source: BSI, OSV, Msrc Update Guide, CVE.org, HKCERT

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 13.5

    Show all metrics
    Severity
    Medium
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    65.95 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    6.9 Methodology
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    6.9
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.2 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    13.5
    Elevated — this CVE ranks above at least 10% of all CVEs scored today.
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    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.

    Source: BSI WID Portal, BSI CSAF, OSV (Open Source Vulnerabilities), Microsoft Security Update Guide, cvelistv5, NVD (NIST), HKCERT (CC BY 3.0 HK) · HKCERT rating: medium

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    Python Software FoundationCPython
    • 3.12.0 – < 3.12.16
    • 3.15.0 – < 3.15.2
    • 3.16.0a1 – < 3.16.0
    • < 3.11.18
    • 3.13.0 – < 3.13.18
    • 3.14.0 – < 3.14.10
    • 3.12.16
    • 3.15.2
    • 3.16.0
    • 3.11.18
    • 3.13.18
    • 3.14.10
    Open SourcePython
    • < 3.14.10
    • < 3.11.18
    • < 3.12.16
    • < 3.16.0
    • < 3.15.2
    • < 3.13.18
    • 3.14.10
    • 3.11.18
    • 3.12.16
    • 3.16.0
    • 3.15.2
    • 3.13.18
    Distribution and container packages (18)

    Downstream packages (e.g. Bitnami, Debian, Ubuntu, Red Hat). Versions refer to the distribution, not the vendor.

    Distribution and container packages
    Affected versionsFixed in
    bitnamilibpython
    • 3.12.0
    • 3.16.0
    • 3.15.0
    • 3.13.0
    • —
    • 3.14.0
    • 3.12.16
    • —
    • 3.15.2
    • 3.13.18
    • 3.11.18
    • 3.14.10
    bitnamipython
    • 3.15.0
    • —
    • 3.13.0
    • 3.16.0
    • 3.14.0
    • 3.12.0
    • 3.15.2
    • 3.11.18
    • 3.13.18
    • —
    • 3.14.10
    • 3.12.16
    bitnamipython-min
    • 3.12.0
    • 3.13.0
    • 3.14.0
    • —
    • 3.16.0
    • 3.15.0
    • 3.12.16
    • 3.13.18
    • 3.14.10
    • 3.11.18
    • —
    • 3.15.2

    Vendors and products

    References & sources

    • github.compython/cpython/pull/160098Patch, web
    • github.compython/cpython/issues/160097Issue tracking, report, web
    • mail.python.orgarchives/list/security-announce@python.org/thread/43JOWPRAV5DI3…web
    • github.compython/cpython/commit/0901ad4ffb22605f12b705d1c1197f0a01f0ba0bfix, Patch, web
    • github.compython/cpython/commit/c6ada40177436e4e2533a7b252082b5f0c043477fix, Patch, web
    • github.compython/cpython/commit/e7e0b3523ad6ba8472873dda594cf4021a16f8b5fix, Patch, web
    • github.compython/cpython/commit/04d8fca7da2cf3ebc0881fec8a53a1330c3b665dfix, Patch, web
    • github.compython/cpython/commit/bc93f8ad4c4a0f92d184ec8fccc8ff8a651dcec2fix, Patch, web
    • github.compython/cpython/commit/f4401da82e2baec5dab06cf070fbca77d53220f0fix, Patch, web
    • NVD (NIST)vuln/detail/CVE-2026-114583web

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedpython.org

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/114xxx/CVE-2026-114583.json">CVE-2026-114583</a>

      Source identifier: cna@python.org

    2. Record modifiedpython.org

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/114xxx/CVE-2026-114583.json">CVE-2026-114583</a>
      Referenceadded
      —
      https://github.com/python/cpython/commit/04d8fca7da2cf3ebc0881fec8a53a1330c3b665d
      Referenceadded
      —
      https://github.com/python/cpython/commit/bc93f8ad4c4a0f92d184ec8fccc8ff8a651dcec2
      Referenceadded
      —
      https://github.com/python/cpython/commit/f4401da82e2baec5dab06cf070fbca77d53220f0

      Source identifier: cna@python.org

    3. Record modifiedpython.org

      Show 3 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://github.com/python/cpython/commit/0901ad4ffb22605f12b705d1c1197f0a01f0ba0b
      Referenceadded
      —
      https://github.com/python/cpython/commit/c6ada40177436e4e2533a7b252082b5f0c043477
      Referenceadded
      —
      https://github.com/python/cpython/commit/e7e0b3523ad6ba8472873dda594cf4021a16f8b5

      Source identifier: cna@python.org

    4. Receivedpython.org

      CVSS V4.0: AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

      Description added or changed

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      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.
      CVSSadded
      —
      AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/114xxx/CVE-2026-114583.json">CVE-2026-114583</a>
      Referenceadded
      —
      https://github.com/python/cpython/issues/160097
      Referenceadded
      —
      https://github.com/python/cpython/pull/160098
      Referenceadded
      —
      https://mail.python.org/archives/list/security-announce@python.org/thread/43JOWPRAV5DI3VZ4FUEUAZOHCATXXOCK/

      Source identifier: cna@python.org

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