SB2026030627 - Ubuntu update for python-bleach
Published: March 6, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 vulnerabilities.
1) Information disclosure (CVE-ID: CVE-2018-7753)
CWE-ID: CWE-229 - Improper Handling of Values
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a remote unauthenticated attacker to bypass sanitization and access sensitive information on the target system.
The weakness exists due to insufficient URI value sanitization. A remote attacker can submit a specially crafted value containing character entities, bypass value sanitization and gain access to potentially sensitive information.
2) Cross-site scripting (CVE-ID: CVE-2020-6802)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code via calling "bleach.clean" with "noscript" and a raw tag in the "allowed/whitelisted" tags option in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
3) Cross-site scripting (CVE-ID: CVE-2020-6816)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data when processing embedded MathML and SVG content with RCDATA tags. A remote attacker can and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
4) Resource management error (CVE-ID: CVE-2020-6817)
CWE-ID: CWE-399 - Resource Management Errors
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to improper input validation when parsing style attrbitues. A remote attacker can create a specially crafted web page that can result in regular expression denial of service (ReDoS).
5) Cross-site scripting (CVE-ID: CVE-2021-23980)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
Remediation
Install update from vendor's website.