MediumCVE-2025-13837

    Out-of-memory when loading Plist (CVE-2025-13837)

    Published Last modified Sources: Red Hat, Debian LTS, SUSE, BSI, OSV, CVE.org, Msrc Update Guide

    What is affected, what to do

    A flaw was found in the plistlib module in the Python standard library. The amount of data to read from a Plist file is specified in the file itself.

    Update Python Software Foundation CPython to version 3.10.20, Python Software Foundation CPython to version 3.11.15, Python Software Foundation CPython to version 3.12.13.

    Affected
    • Python Software Foundation CPython lt *..3.10.20
    • Python Software Foundation CPython lt 3.11.0..3.11.15
    • Python Software Foundation CPython lt 3.12.0..3.12.13
    • Python Software Foundation CPython lt 3.13.0..3.13.10
    • Python Software Foundation CPython lt 3.14.0..3.14.1
    • Python Software Foundation CPython lt 3.15.0a1..3.15.0a3
    Fixed in
    • Python Software Foundation CPython 3.10.20
    • Python Software Foundation CPython 3.11.15
    • Python Software Foundation CPython 3.12.13
    • Python Software Foundation CPython 3.13.10
    • Python Software Foundation CPython 3.14.1
    • Python Software Foundation CPython 3.15.0a3

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

    Metrics

    5.5

    Priority

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

    Source: NVD, CVSS v3

    5.5

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: Red Hat, Debian LTS, SUSE, BSI, OSV, CVE.org, Msrc Update Guide

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 12.9

    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
    41.29 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
    5.5 Methodology
    CVSS v3

    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
    5.5
    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
    2.1
    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
    12.9
    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
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 1 December 2025
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-400

    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

    A flaw was found in the plistlib module in the Python standard library. The amount of data to read from a Plist file is specified in the file itself. This issue allows a specially crafted Plist file to cause an application to allocate a large amount of memory, potentially resulting in allocations errors, swapping, out-of-memory conditions or even system freezes.

    Source: redhat_csaf, Debian LTS Advisories, suse_csaf, BSI WID Portal, BSI CSAF, OSV (Open Source Vulnerabilities), cvelistv5, NVD (NIST), CVE.org (MITRE), Microsoft Security Update Guide

    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 – < 3.12.13
    • < 3.10.20
    • 3.15.0a1 – < 3.15.0a3
    • 3.13.0 – < 3.13.10
    • 3.11.0 – < 3.11.15
    • 3.14.0 – < 3.14.1
    • 3.12.13
    • 3.10.20
    • 3.15.0a3
    • 3.13.10
    • 3.11.15
    • 3.14.1
    pythonpython
    • 3.14.0 – < 3.14.1
    • 3.15.0
    • < 3.13.10
    • 3.14.1
    • —
    • 3.13.10
    OracleSiebel CRM
    • 17.0-26.5
    • —
    Distribution and container packages (4)

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

    Distribution and container packages
    Affected versionsFixed in
    bitnamipython-min
    • 3.13.0
    • 3.12.0
    • 3.14.0
    • 3.11.0
    • —
    • —
    • —
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianpython3.9bullseye

    Weakness classes (CWE)

    • CWE-400Uncontrolled Resource Consumption

      Class

      The product does not properly control the allocation and maintenance of a limited resource.

      Entry at MITRE CWE-400

    References & sources

    • github.compython/cpython/pull/119343web, Patch
    • github.compython/cpython/issues/119342report, Issue tracking
    • github.compython/cpython/commit/694922cf40aa3a28f898b5f5ee08b71b4922df70fix, Patch
    • github.compython/cpython/commit/71fa8eb8233b37f16c88b6e3e583b461b205d1bafix, Patch
    • github.compython/cpython/commit/b64441e4852383645af5b435411a6f849dd1b4cbfix, Patch
    • mail.python.orgarchives/list/security-announce@python.org/thread/2X5IBCJXRQAZ5…advisory, Vendor advisory
    • github.compython/cpython/commit/5a8b19677d818fb41ee55f310233772e15aa1a2bfix, Patch
    • github.compython/cpython/commit/568342cfc8f002d9a15f30238f26b9d2e0e79036fix, Patch
    • github.compython/cpython/commit/cefee7d118a26ef6cd43db59bb9d98ca9a331111fix, Patch
    • NVD (NIST)vuln/detail/CVE-2025-13837web

    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

      Show 25 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://github.com/python/cpython/commit/568342cfc8f002d9a15f30238f26b9d2e0e79036
      Referenceadded
      —
      https://github.com/python/cpython/commit/5a8b19677d818fb41ee55f310233772e15aa1a2b
      Referenceadded
      —
      https://github.com/python/cpython/commit/694922cf40aa3a28f898b5f5ee08b71b4922df70
      Referenceadded
      —
      https://github.com/python/cpython/commit/71fa8eb8233b37f16c88b6e3e583b461b205d1ba
      Referenceadded
      —
      https://github.com/python/cpython/commit/b64441e4852383645af5b435411a6f849dd1b4cb
      Referenceadded
      —
      https://github.com/python/cpython/commit/cefee7d118a26ef6cd43db59bb9d98ca9a331111
      Referenceadded
      —
      https://github.com/python/cpython/issues/119342
      Referenceadded
      —
      https://github.com/python/cpython/pull/119343
      Referenceadded
      —
      https://mail.python.org/archives/list/security-announce@python.org/thread/2X5IBCJXRQAZ5PSERLHMSJFBHFR3QM2C/
      Referenceremoved
      https://github.com/python/cpython/commit/568342cfc8f002d9a15f30238f26b9d2e0e79036
      —
      Referenceremoved
      https://github.com/python/cpython/commit/5a8b19677d818fb41ee55f310233772e15aa1a2b
      —
      Referenceremoved
      https://github.com/python/cpython/commit/694922cf40aa3a28f898b5f5ee08b71b4922df70
      —
      Referenceremoved
      https://github.com/python/cpython/commit/71fa8eb8233b37f16c88b6e3e583b461b205d1ba
      —
      Referenceremoved
      https://github.com/python/cpython/commit/b64441e4852383645af5b435411a6f849dd1b4cb
      —
      Referenceremoved
      https://github.com/python/cpython/commit/cefee7d118a26ef6cd43db59bb9d98ca9a331111
      —
      Referenceremoved
      https://github.com/python/cpython/issues/119342
      —
      Referenceremoved
      https://github.com/python/cpython/pull/119343
      —
      Referenceremoved
      https://mail.python.org/archives/list/security-announce@python.org/thread/2X5IBCJXRQAZ5PSERLHMSJFBHFR3QM2C/
      —
      Reference typeremoved
      https://github.com/python/cpython/commit/5a8b19677d818fb41ee55f310233772e15aa1a2b Types: Patch
      —
      Reference typeremoved
      https://github.com/python/cpython/commit/694922cf40aa3a28f898b5f5ee08b71b4922df70 Types: Patch
      —
      Reference typeremoved
      https://github.com/python/cpython/commit/71fa8eb8233b37f16c88b6e3e583b461b205d1ba Types: Patch
      —
      Reference typeremoved
      https://github.com/python/cpython/commit/b64441e4852383645af5b435411a6f849dd1b4cb Types: Patch
      —
      Reference typeremoved
      https://github.com/python/cpython/issues/119342 Types: Issue Tracking, Patch
      —
      Reference typeremoved
      https://github.com/python/cpython/pull/119343 Types: Issue Tracking, Patch
      —
      Reference typeremoved
      https://mail.python.org/archives/list/security-announce@python.org/thread/2X5IBCJXRQAZ5PSERLHMSJFBHFR3QM2C/ Types: Vendor Advisory
      —

      Source identifier: cna@python.org

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentchanged
      {"id":"CVE-2025-13837","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2025-12-01T18:23:28.615317Z"}
      {"id":"CVE-2025-13837","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2025-12-01T18:23:28.615317Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

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