CVE-2026-115758

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    CVE-2026-115758

    Published: 4 Nov 2026Last Modified: 6 Nov 2026

    Summary: SumatraPDF: TLS hostname validation disabled in `HttpGet()`

    Details: SumatraPDF is a multi-format reader for Windows. In version 3.6.1 and earlier, HttpGet() in src/base/Http_win.cpp unconditionally passes INTERNET_FLAG_IGNORE_CERT_CN_INVALID to WinINet, disabling hostname matching for HTTPS update metadata and crash-symbol requests while retaining certificate-chain validation. A network-positioned attacker with a Windows-trusted certificate for an attacker-controlled domain can impersonate the project's update host, inject promo text and a clickable URL before update metadata validation, and provide an attacker-controlled archive to ExtractSymbols(). Installer replacement is not directly possible because HttpGetToFile() validates TLS and MaybeStartUpdateDownload() restricts the download host. No fixed version is available as of this review.

    References: https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/115xxx/CVE-2026-115758.json, https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-mjwr-9w29-jp96, https://nvd.nist.gov/vuln/detail/CVE-2026-115758, https://github.com/sumatrapdfreader/sumatrapdf/commit/bd30134175e897dd5ed0d7fd14acce52eeca7183

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -bd30134175e897dd5ed0d7fd14acce52eeca7183

    Affected versions

    3.2

    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-2026-115758 | CVE-DB