CVE-2021-27903
Craft CMS Remote Code Injection
An issue was discovered in Craft CMS before 3.6.7. In some circumstances, a potential Remote Code Execution vulnerability existed on sites that did not restrict administrative changes (if an attacker were somehow able to hijack an administrator's session).
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in Craft CMS before 3.6.7. In some circumstances, a potential Remote Code Execution vulnerability existed on sites that did not restrict administrative changes (if an attacker were somehow able to hijack an administrator's session).
- Record
CVE-2021-27903- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-862
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in Craft CMS before 3.6.7. In some circumstances, a potential Remote Code Execution vulnerability existed on sites that did not restrict administrative changes (if an attacker were somehow able to hijack an administrator's session).
- Record
CVE-2021-27903- Updated
- 2026-11-02
EUVDEUVD-2021-1499 No score
An issue was discovered in Craft CMS before 3.6.7. In some circumstances, a potential Remote Code Execution vulnerability existed on sites that did not restrict administrative changes (if an attacker were somehow able to hijack an administrator's session).
- Record
EUVD-2021-1499- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-x2j7-6hxm-87p3
Craft CMS Remote Code Injection
An issue was discovered in Craft CMS before 3.6.7. In some circumstances, a potential Remote Code Execution vulnerability existed on sites that did not restrict administrative changes (if an attacker were somehow able to hijack an administrator's session).
- Record
GHSA-x2j7-6hxm-87p3- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-74, CWE-94
- Updated
- 2026-11-02
OSV
An issue was discovered in Craft CMS before 3.6.7. In some circumstances, a potential Remote Code Execution vulnerability existed on sites that did not restrict administrative changes (if an attacker were somehow able to hijack an administrator's session).
- Record
CVE-2021-27903- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-x2j7-6hxm-87p3
Craft CMS Remote Code Injection
An issue was discovered in Craft CMS before 3.6.7. In some circumstances, a potential Remote Code Execution vulnerability existed on sites that did not restrict administrative changes (if an attacker were somehow able to hijack an administrator's session).
- Record
GHSA-x2j7-6hxm-87p3- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-74, CWE-94
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
craftcms/cmsPackagist |
before 3.6.7 | 3.6.7 |
craftcms/cmsPackagist |
before 3.6.7, plus listed versions 1.0.26.11.2.0-alpha.23101.2.0-alpha.23121.2.0-alpha.23161.2.0-alpha.2318 Show 45 moreShow less1.2.0-alpha.23191.2.0-alpha.23221.2.0-alpha.23231.2.0-alpha.23241.2.0-alpha.23281.2.0-alpha.23291.2.0-alpha.23321.2.23331.2.23351.2.23361.2.23371.2.23391.2.23581.2.23631.2.23671.2.23711.2.23751.2.23871.2.23921.2.23961.2.23991.3.0-alpha.23611.3.0-alpha.23661.3.0-alpha.23721.3.0-alpha.23741.3.0-alpha.23771.3.0-alpha.23781.3.0-alpha.23801.3.0-alpha.23881.3.0-alpha.23941.3.0-alpha.23971.3.0-alpha.24011.3.0-alpha.24021.3.0-alpha.24051.3.0-alpha.24641.3.24091.3.24101.3.24151.3.24161.3.24181.3.24191.3.24201.3.24221.3.24561.3.2459 |
3.6.7 |
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-2021-27903 is a critical vulnerability (CVSS 9.8) in Craftcms Craft Cms, published June 30, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.82%, the 86th percentile. Fixed in craftcms/cms 3.6.7.
References
Left out here: 636 versions. The JSON record has them.