xygeni xygeni-action malicious code

Summaryinfo

A vulnerability, which was classified as critical, has been found in xygeni xygeni-action. This affects an unknown part. The manipulation leads to malicious code. This vulnerability is documented as CVE-2026-31976. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in xygeni xygeni-action (affected version unknown). This issue affects an unknown functionality. The manipulation with an unknown input leads to a malicious code vulnerability. Using CWE to declare the problem leads to CWE-506. The product contains code that appears to be malicious in nature. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-31976 since 03/10/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/17/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-11331). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• xygeni

Name

• xygeni-action

Website

• Product: https://github.com/xygeni/xygeni-action/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion