CVE-2026-21861: baserproject basercms · OS Command Injection
Affects baserproject basercmsSource CVE Database V5
Not known to be exploited · CVSS 9.1 Critical : upgrade to 5.2.3 as a priority.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 2.3% chance of exploitation in 30 days – higher than 83% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.2.3
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 31 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade basercms and baserproject/basercms to 5.2.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| baserprojectbasercms | Affected
| Fixed in
|
GitHubbaserproject/basercmspkg:github/baserproject/basercmsOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade baserCMS to version 5.2.3 or later, where this vulnerability has been patched. No other mitigations are specified or required once the official fix is applied.
Description
baserCMS versions prior to 5.2.3 contain a critical OS command injection vulnerability in the core update functionality. An authenticated administrator can exploit this flaw to execute arbitrary operating system commands on the server. The vulnerability arises from improper neutralization of special elements in user input passed directly to the exec() function without adequate validation or escaping. This issue has been addressed and patched in version 5.2.3.