# CVE-2026-40042: Pachno 1.0.6 Wiki TextParser XML External Entity Injection

> Unauthenticated attackers can read arbitrary files via XML external entity injection in Pachno wiki text parsing.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Apr 2026
- **Updated:** 12 May 2026
- **Also known as:** GHSA-5j7x-7mp7-c5xc

## What is CVE-2026-40042?

CVE-2026-40042 is a critical vulnerability in Pachno, published on 13 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Pachno 1.0.6 contains an XML external entity injection vulnerability that allows unauthenticated attackers to read arbitrary files by exploiting unsafe XML parsing in the TextParser helper. Attackers can inject malicious XML entities through wiki table syntax and inline tags in issue descriptions, comments, and wiki articles to trigger entity resolution via simplexml_load_string() without LIBXML_NONET restrictions.

Weakness: CWE-403 (Exposure of File Descriptor to Unintended Control Sphere)

## Which versions are affected by CVE-2026-40042?


## How do I fix CVE-2026-40042?

No fix has been published for CVE-2026-40042 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-40042 being exploited?

There is no known exploitation of CVE-2026-40042 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40042 and fix it if it is affected.

What it is: CVE-2026-40042 is a critical vulnerability in Pachno, published on 13 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-40042 in the wild and no public exploit code.

Affected product: Pachno. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-40042/ (Markdown: https://insights.sbomify.com/CVE-2026-40042/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40042
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40042
- OSV: https://osv.dev/vulnerability/CVE-2026-40042

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40042/
Summaries are generated and may contain mistakes; the official description above is the record.