CVE-2026-21861
CVE-2026-21861 — baserCMS: OS Command Injection Leading to Remote Code Execution (RCE)
baserCMS is a website development framework. Prior to version 5.2.3, baserCMS contains an OS command injection vulnerability in the core update functionality. An authenticated administrator can execute arbitrary OS commands on the server due to improper handling of user-controlled input that is directly passed to exec() without sufficient validation or escaping. This issue has been patched in version 5.2.3.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
2%
chance of exploitation in 30 days
CVSS base
9.1
CRITICAL
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
PoC
none · proof-of-concept · active
Automatable
No
can an attacker script all four kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 9.1 | CVSS 3.1 | CRITICAL | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-78
References
3 on the record
- github.com/baserproject/basercms/security/advisories/GHSA-qxmc-6f24-g86g
x_refsource_CONFIRM
- basercms.net/security/JVN_20837860
x_refsource_MISC
- github.com/baserproject/basercms/releases/tag/5.2.3
x_refsource_MISC
Elsewhere on this site
- baserprojectevery CVE for this vendor
- CWE-78other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.