BIT-pillow-2026-96640

    Dashboard / Vulnerabilities / BIT-pillow-2026-96640

    BIT-pillow-2026-96640

    Published: 29 Oct 2026Last Modified: 29 Oct 2026

    Summary: Pillow PDF append accepts malformed shared page-tree DAG causing resource exhaustion

    Details: Pillow is a Python imaging library. From 5.1.0 until 13.0.0, PdfParser.linearize_page_tree() in src/PIL/PdfParser.py treats a PDF /Pages graph as a tree without tracking duplicate indirect references. When Image.save(..., format="PDF", append=True) processes an attacker-controlled existing PDF whose /Kids arrays repeatedly reference the same child /Pages node, Pillow expands the shared subtree as distinct pages. A compact malformed PDF can therefore create exponentially many page references and consume disproportionate CPU before the append completes. This issue is fixed in version 13.0.0.

    References: https://github.com/python-pillow/Pillow/commit/6f0e7ee1f9c2fe227906f8a4b926e6622b702bc7, https://github.com/python-pillow/Pillow/pull/10093, https://github.com/python-pillow/Pillow/releases/tag/13.0.0, https://github.com/python-pillow/Pillow/security/advisories/GHSA-mrfp-p49p-3hf2, https://nvd.nist.gov/vuln/detail/CVE-2026-96640

    Affected packages

    Package

    Name: pillow

    Purl: pkg:bitnami/pillow

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 5.1.0
    Fixed -13.0.0

    Affected versions

    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