CVE-2026-78834: CMSimple · CVE-2026-78834 is a high-severity code execution
Source CVE Database V5
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
AI-suggested
Until a fix is available, restrict access to the content import feature to trusted users only and monitor for suspicious activity related to content imports.
Description
CVE-2026-78834 is a high-severity code execution vulnerability in CMSimple 5.22 affecting the CoAuthors plugin. It allows an authenticated low-privileged user with permission to modify page content to trigger server-side code execution by importing crafted external or uploaded text content through the content import feature.