CVE-2026-31976xygeni-action is the GitHub Action for Xygeni Scanner.

xygeni-action is the GitHub Action for Xygeni Scanner. On March 3, 2026, an attacker with access to compromised credentials created a series of pull requests (#46, #47, #48) injecting obfuscated shell code into action.yml. The PRs were blocked by branch protection rules and never merged into the main branch. However, the attacker used the compromised GitHub App credentials to move the mutable v5 tag to point at the malicious commit (4bf1d4e19ad81a3e8d4063755ae0f482dd3baf12) from one of the unmerged PRs. This commit remained in the repository's git object store, and any workflow referencing @v5 would fetch and execute it. This is a supply chain compromise via tag poisoning. Any GitHub Actions workflow referencing xygeni/xygeni-action@v5 during the affected window (approximately March 3–10, 2026) executed a C2 implant that granted the attacker arbitrary command execution on the CI runner for up to 180 seconds per workflow run.

CVSS

9.8 CRITICAL (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness (CWE)

CWE-506

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Not given

NVD analysis

Analyzed

Record last updated

Jun 17, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.