CVE-2023-36810

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    CVE-2023-36810

    Published: 30 Jun 2023Last Modified: 12 Aug 2026

    Summary: Quadratic runtime with malformed PDF missing xref marker in pypdf

    Details: pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. This issue has been addressed in PR 808 and versions from 1.27.9 include this fix. Users are advised to upgrade. There are no known workarounds for this vulnerability.

    References: https://lists.debian.org/debian-lts-announce/2023/07/msg00019.html, https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/36xxx/CVE-2023-36810.json, https://github.com/py-pdf/pypdf/security/advisories/GHSA-jrm6-h9cq-8gqw, https://nvd.nist.gov/vuln/detail/CVE-2023-36810, https://github.com/py-pdf/pypdf/issues/582, https://github.com/py-pdf/pypdf/pull/808

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -22033d724e0c8a684c5aca1d390deedb4331a273

    Affected versions

    1.27.8
    1.27.7
    1.27.6
    1.27.5
    1.27.4
    1.27.3
    1.27.2
    1.27.1
    1.27.0

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2023-36810 | CVE-DB