USN-8077-1

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    USN-8077-1

    Published: 5 Mar 2026Last Modified: 25 Jun 2026

    Summary: python-bleach vulnerabilities

    Details: It was discovered that Bleach did not properly sanitize URI attributes containing character entities. An attacker could possibly use this issue to construct a URI with a disallowed scheme that would bypass sanitization, leading to cross-site scripting. This issue only affected Ubuntu 18.04 LTS. (CVE-2018-7753) Yaniv Nizry discovered that Bleach was vulnerable to a mutation cross-site scripting issue when sanitizing HTML with the noscript tag and a raw tag in the allowed tags list. An attacker could possibly use this issue to inject malicious content, leading to cross-site scripting. This issue only affected Ubuntu 18.04 LTS. (CVE-2020-6802) Yaniv Nizry discovered that Bleach was vulnerable to a mutation cross-site scripting issue when sanitizing HTML with RCDATA together with svg or math tags in the allowed tags list. An attacker could possibly use this issue to inject malicious content, leading to cross-site scripting. (CVE-2020-6816) It was discovered that Bleach incorrectly handled parsing of style attributes when sanitizing HTML. An attacker could possibly use this issue to perform a regular expression denial of service, leading to excessive resource consumption. (CVE-2020-6817) Yaniv Nizry and Michał Bentkowski discovered that Bleach was vulnerable to a mutation cross-site scripting issue when sanitizing HTML with certain combinations of allowed tags. An attacker could possibly use this issue to inject malicious content, leading to cross-site scripting. (CVE-2021-23980)

    Affected packages

    Package

    Name: python-bleach

    Purl: pkg:deb/ubuntu/python-bleach?arch=source&distro=esm-apps%2Fxenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -1.4.2-1ubuntu0.1~esm1

    Affected versions

    1.4-1

    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