CVE-2026-115481
baserCMS: BcCustomContent file fields can be configured to allow executable file extensions such as php, leading to arbitrary PHP file upload
baserCMS is a website development framework. Starting in version 5.0.0-beta1 and prior to versions 5.3.2 and 5.4.2, PermissionGroupsService::build() reads a plugin's config/permission.php to decide what each user group may reach. When that file is absent it writes a wildcard allow rule instead: url /baser/<prefix>/<plugin>/*, method *, auth true, for every non-admin group. BcCustomContent has no such file in any release. After an administrator installs it, the default operators group can store and execute arbitrary PHP under the document root. Versions 5.3.2 and 5.4.2 patch the issue.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Active
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.5
baserCMS: BcCustomContent file fields can be configured to allow executable file extensions such as php, leading to arbitrary PHP file upload
baserCMS is a website development framework. Starting in version 5.0.0-beta1 and prior to versions 5.3.2 and 5.4.2, PermissionGroupsService::build() reads a plugin's config/permission.php to decide what each user group may reach. When that file is absent it writes a wildcard allow rule instead: url /baser/<prefix>/<plugin>/*, method *, auth true, for every non-admin group. BcCustomContent has no such file in any release. After an administrator installs it, the default operators group can store and execute arbitrary PHP under the document root. Versions 5.3.2 and 5.4.2 patch the issue.
- Record
CVE-2026-115481- CVSS 4.0
- 8.5 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-434
- Updated
- 2026-11-02
EUVDEUVD-2026-108983
8.5
baserCMS is a website development framework. Starting in version 5.0.0-beta1 and prior to versions 5.3.2 and 5.4.2, PermissionGroupsService::build() reads a plugin's config/permission.php to decide what each user group may reach. When that file is absent it writes a wildcard allow rule instead: url /baser/<prefix>/<plugin>/*, method *, auth true, for every non-admin group. BcCustomContent has no such file in any release. After an administrator installs it, the default operators group can store and execute arbitrary PHP under the document root. Versions 5.3.2 and 5.4.2 patch the issue.
- Record
EUVD-2026-108983- CVSS 4.0
- 8.5 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
NVD
8.5
baserCMS is a website development framework. Starting in version 5.0.0-beta1 and prior to versions 5.3.2 and 5.4.2, PermissionGroupsService::build() reads a plugin's config/permission.php to decide what each user group may reach. When that file is absent it writes a wildcard allow rule instead: url /baser/<prefix>/<plugin>/*, method *, auth true, for every non-admin group. BcCustomContent has no such file in any release. After an administrator installs it, the default operators group can store and execute arbitrary PHP under the document root. Versions 5.3.2 and 5.4.2 patch the issue.
- Record
CVE-2026-115481- CVSS 4.0
- 8.5 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-434
- Updated
- 2026-11-02
OSV
8.5
baserCMS: BcCustomContent file fields can be configured to allow executable file extensions such as php, leading to arbitrary PHP file upload
baserCMS is a website development framework. Starting in version 5.0.0-beta1 and prior to versions 5.3.2 and 5.4.2, PermissionGroupsService::build() reads a plugin's config/permission.php to decide what each user group may reach. When that file is absent it writes a wildcard allow rule instead: url /baser/<prefix>/<plugin>/*, method *, auth true, for every non-admin group. BcCustomContent has no such file in any release. After an administrator installs it, the default operators group can store and execute arbitrary PHP under the document root. Versions 5.3.2 and 5.4.2 patch the issue.
- Record
CVE-2026-115481- CVSS 4.0
- 8.5 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-434
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-115481 is a high vulnerability (CVSS 8.5) in Baserproject Basercms, published October 23, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.40%, the 34th percentile. No source names a fixed version.
References
github.com/baserproject/basercms/security/advisories/GHSA-8jrp-4h7c-m679
github.com/baserproject/basercms/commit/2ed19c878add5c26fc765572e0e77173c1f1fdb5
github.com/baserproject/basercms/commit/b0ef31b10dc6267b48ebc9a80d34bc7c4c09c311
github.com/baserproject/basercms/releases/tag/5.3.2
github.com/baserproject/basercms/releases/tag/5.4.2
github.com/CVEProject/cvelistV5/tree/main/cves/2026/115xxx/CVE-2026-115481.json
nvd.nist.gov/vuln/detail/CVE-2026-115481