Security Digest · Vulnerability record
CVE-2026-34243: wenxian: Command Injection in GitHub Actions Workflow via `issue_comment.body`
wenxian is a tool to generate BIBTEX files from given identifiers (DOI, PMID, arXiv ID, or paper title).
CVSS 9.8 Critical EPSS 2.8% · p86
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 2.8%, percentile 86: FIRST’s model estimates a 2.8% chance of exploitation activity in the next 30 days, higher than 86% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
njzjz/wenxian(GitHub Actions) <= 0.3.1, no fixed version listed. Check your lockfile, including transitive dependencies.
What it is
wenxian is a tool to generate BIBTEX files from given identifiers (DOI, PMID, arXiv ID, or paper title). In versions 0.3.1 and prior, a GitHub Actions workflow uses untrusted user input from issuecomment.body directly inside a shell command, allowing potential command injection and arbitrary code execution on the runner. At time of publication, there are no publicly available patches.
From the GitHub advisory
Summary
A GitHub Actions workflow uses untrusted user input from issuecomment.body directly inside a shell command, allowing potential command injection and arbitrary code execution on the runner.
Details
The workflow is triggered by issuecomment, which can be controlled by external users. In the following step:
the value of github.event.comment.body is directly interpolated into a shell command inside run:.
Weakness type: CWE-77, CWE-78, CWE-20.
Product: njzjz/wenxian (GitHub Actions) · Assigned by: GitHub_M · Published: 2026-03-31
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| GitHub Actions | njzjz/wenxian | <= 0.3.1 | none listed |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| njzjz | wenxian | <= 0.3.1 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: unchanged
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 2.78% probability of exploitation activity in the next 30 days; percentile 86.
Timeline
- — GitHub-reviewed advisory GHSA-r4fj-r33x-8v88 published (critical)
- — CVE record published by GitHub_M
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-r4fj-r33x-8v88 github.com
- CVE.org record CVE-2026-34243 cve.org
- NVD entry CVE-2026-34243 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
Critical GitHub Actions advisories · Today’s Security Digest