CVE-2020-25817
SilverStripe XXE Vulnerability in CSSContentParser
SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
4.8
SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).
- Record
CVE-2020-25817- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-611
- Updated
- 2026-11-02
CVE List No score
SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).
- Record
CVE-2020-25817- Updated
- 2026-11-02
EUVDEUVD-2022-2244 No score
SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).
- Record
EUVD-2022-2244- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3vjc-5x79-m9r8
4.8
SilverStripe XXE Vulnerability in CSSContentParser
SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).
- Record
GHSA-3vjc-5x79-m9r8- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-611
- Updated
- 2026-11-02
OSV
4.8
SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).
- Record
CVE-2020-25817- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-3vjc-5x79-m9r8
4.8
SilverStripe XXE Vulnerability in CSSContentParser
SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).
- Record
GHSA-3vjc-5x79-m9r8- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-611
- Updated
- 2026-11-02
OSVBIT-silverstripe-2020-25817 No score
SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).
- Record
BIT-silverstripe-2020-25817- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
silverstripe/frameworkPackagist |
4.0.0 up to 4.7.4 | 4.7.4 |
silverstripeBitnami |
before 4.6.0, 4.6.0-rc1 to 4.6.0-rc1 | 4.6.0 |
silverstripe/frameworkPackagist |
4.0.0 up to 4.7.4, plus listed versions 4.0.14.0.1-rc14.0.24.0.34.0.4 Show 45 moreShow less4.0.54.0.64.0.74.1.04.1.0-rc14.1.0-rc24.1.14.1.24.1.34.1.44.1.54.2.04.2.0-beta14.2.14.2.24.2.34.2.44.2.54.3.04.3.0-rc14.3.14.3.24.3.34.3.44.3.54.4.04.4.0-rc14.4.14.4.24.4.34.4.44.4.54.4.64.4.74.5.04.5.0-alpha14.5.0-rc14.5.0-rc24.5.14.5.24.5.34.5.44.6.04.6.0-beta14.6.0-rc1 |
4.7.4 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-25817 is a medium vulnerability (CVSS 4.8) in Silverstripe, published June 8, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.82%, the 57th percentile. Fixed in silverstripe/framework 4.7.4.
References
silverstripe.org/download/security-releases
silverstripe.org/blog/tag/release
forum.silverstripe.org/c/releases
silverstripe.org/download/security-releases/cve-2020-25817
nvd.nist.gov/vuln/detail/CVE-2020-25817
silverstripe.org/download/security-releases/cve-2021-25817
github.com/advisories/GHSA-3vjc-5x79-m9r8
github.com/silverstripe/silverstripe-framework
Left out here: 8 versions. The JSON record has them.