CKAN MCP Server: DataStore Table UI resource does not validate postMessage origin (in) and posts to targetOrigin "*" (out)
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 0.4.112
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 0.4.112.
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure7/25Reachable over the network without a login · Data gap: No advisory context yet
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity3.1/10CVSS 3.1
- No patch0/5No signal
What would change the score
- Would score about 65 if added to CISA KEV
- Would score about 60 if CISA's SSVC rates exploitation active
- Would score about 25 if advisories confirm default setups are exposed
CVE-2026-76894 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 3.1 (low) and affects ckan-mcp-server; fixed in 0.4.112.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 10/100 · provisional
- Fix
- Fixed in 0.4.112
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The CKAN MCP Server, a tool for querying CKAN open data portals, has a DataStore table UI component that accepts messages from any origin and sends messages to any origin. An attacker-controlled frame could inject fake records or fields, disrupt the UI handshake, or receive data sent by the component, which could lead to misleading displayed content and data exposure.
Read the original description
CKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, the DataStore table UI in src/resources/datastore-table-ui.ts accepts window message events without validating event.origin and sends JSON-RPC messages through postMessage with a wildcard target origin. A frame that can reach the embedded document can inject fabricated fields or records, spoof pending ui/initialize responses, disrupt the MCP UI handshake, or receive outbound messages when the resource is embedded by an untrusted parent. Values are HTML escaped, so the demonstrated content injection is display spoofing rather than script execution, and exploitability depends on the host embedding model. This issue is fixed in version 0.4.112.
What to do
Upgrade to a fixed version: 0.4.112.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- ondata ckan-mcp-server
fixed in 0.4.112
Evidence 3
- Advisory
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-76894
Is CVE-2026-76894 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-76894?
ckan-mcp-server: before 0.4.112.Source: cve.now feed data
How do I fix CVE-2026-76894?
Upgrade to a fixed version: 0.4.112.Source: cve.now feed data