Vulnerability Details : CVE-2020-26293
HtmlSanitizer is a .NET library for cleaning HTML fragments and documents from constructs that can lead to XSS attacks. In HtmlSanitizer before version 5.0.372, there is a possible XSS bypass if style tag is allowed. If you have explicitly allowed the `<style>` tag, an attacker could craft HTML that includes script after passing through the sanitizer. The default settings disallow the `<style>` tag so there is no risk if you have not explicitly allowed the `<style>` tag. The problem has been fixed in version 5.0.372.
Vulnerability category: Cross site scripting (XSS)
Products affected by CVE-2020-26293
- cpe:2.3:a:htmlsanitizer_project:htmlsanitizer:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2020-26293
0.12%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 46 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2020-26293
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
4.3
|
MEDIUM | AV:N/AC:M/Au:N/C:N/I:P/A:N |
8.6
|
2.9
|
NIST | |
|
6.1
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
2.8
|
2.7
|
NIST | |
|
6.1
|
MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N |
1.6
|
4.0
|
GitHub, Inc. |
CWE ids for CVE-2020-26293
-
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.Assigned by: security-advisories@github.com (Secondary)
-
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.Assigned by: nvd@nist.gov (Primary)
References for CVE-2020-26293
-
https://www.nuget.org/packages/HtmlSanitizer/
NuGet Gallery | HtmlSanitizer 5.0.372Product;Third Party Advisory
-
https://github.com/mganss/HtmlSanitizer/releases/tag/v5.0.372
Release 5.0.372 · mganss/HtmlSanitizer · GitHubRelease Notes;Third Party Advisory
-
https://github.com/mganss/HtmlSanitizer/security/advisories/GHSA-8j9v-h2vp-2hhv
Possible XSS bypass if style tag is allowed · Advisory · mganss/HtmlSanitizer · GitHubThird Party Advisory
-
https://github.com/mganss/HtmlSanitizer/commit/a3a7602a44d4155d51ec0fbbedc2a49e9c7e2eb8
Fix hex escape issue in style element · mganss/HtmlSanitizer@a3a7602 · GitHubPatch;Third Party Advisory
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