# CVE-2026-73846: CKAN MCP Server: Cache-key canonicalization collision enables cache confusion / poisoning

> An attacker can poison the shared cache by exploiting parameter serialization flaws, causing victims to receive incorrect or malicious data.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** GHSA-78x9-fhhx-v2g6

## What is CVE-2026-73846?

CVE-2026-73846 is a medium-severity vulnerability in ondata ckan-mcp-server, published on 14 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

CKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, canonicalizeParams in src/utils/cache.ts serializes request parameters with unescaped ampersand, equals-sign, and vertical-bar delimiters, allowing different logical parameter sets used by buildCacheKey to collide and an attacker to prime a shared cache with a response for a victim's distinct query. This issue is fixed in version 0.4.112.

Weakness: CWE-436 (Interpretation Conflict), CWE-345 (Insufficient Verification of Data Authenticity)

## Which versions are affected by CVE-2026-73846?

2 open source packages ship an affected version, including @aborruso/ckan-mcp-server.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@aborruso/ckan-mcp-server` | npm | All versions | 0.4.112 |
| `@aborruso/ckan-mcp-server` | npm | All versions | 0.4.112 |

## How do I fix CVE-2026-73846?

Upgrade @aborruso/ckan-mcp-server to 0.4.112 or later.

## Is CVE-2026-73846 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73846 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73846 and fix it if it is affected.

What it is: CVE-2026-73846 is a medium-severity vulnerability in ondata ckan-mcp-server, published on 14 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73846 exists.

Affected packages and fixed versions:
- @aborruso/ckan-mcp-server (npm): affected all versions; fixed in 0.4.112
- @aborruso/ckan-mcp-server (npm): affected all versions; fixed in 0.4.112

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-73846/ (Markdown: https://insights.sbomify.com/CVE-2026-73846/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73846
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73846
- OSV: https://osv.dev/vulnerability/CVE-2026-73846

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73846/
Summaries are generated and may contain mistakes; the official description above is the record.