CVE-2026-31976
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedxygeni-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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceAn attacker compromised GitHub App credentials and used them to move the mutable v5 tag to point at a malicious commit containing obfuscated shell code. Any GitHub Actions workflow referencing xygeni/xygeni-action@v5 during March 3-10, 2026 executed a C2 implant granting arbitrary command execution on CI runners.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 5.38.0, <= 6.4.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify workflows referencing the v5 tagSearch your repository workflows (in .github/workflows/) for 'xygeni/xygeni-action@v5' or '@v5' to see if any workflows use this mutable tag reference.Affected if Workflows contain references to 'xygeni/xygeni-action@v5' without a pinned commit SHA or fixed version.
-
Check for workflow runs during the affected windowReview GitHub Actions workflow run history to identify any executions that occurred between March 3-10, 2026 that used the v5 tag.Affected if Workflows using the v5 tag executed during March 3-10, 2026.
-
Inspect the resolved commit SHAFor workflow runs that used v5 during the affected window, examine the resolved commit SHA in the workflow run logs and compare it against the expected legitimate commit for that version.Affected if The resolved commit SHA differs from the legitimate xygeni-action repository state or points to an unexpected commit.
-
Review CI runner execution logsExamine GitHub Actions run logs for the affected period for any unexpected shell command executions, network connections to unknown hosts, or unusual artifact downloads.Affected if Logs show unexpected commands, external C2 communications, or suspicious script execution originating from the xygeni-action.
You are affected if you have GitHub Actions workflows using xygeni/xygeni-action@v5 that executed between March 3-10, 2026, as the mutable tag may have resolved to a malicious commit during that window.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUsers must immediately update workflows to use a pinned immutable commit SHA or a fixed version instead of @v5, audit CI logs for the affected window for indicators of compromise, and rotate any credentials that may have been exposed.
xygeni/[email protected] or later (or a specific safe commit SHA)
- 1. Immediately stop using xygeni/xygeni-action@v5 in any GitHub Actions workflow
- 2. Identify the last known safe commit or version before the poisoning window (before March 3, 2026)
- 3. Update workflow files to reference an immutable reference: either a specific version tag (e.g., @v5.38.0) or the full commit SHA
- 4. Verify the referenced version is not in the affected commit range (4bf1d4e19ad81a3e8d4063755ae0f482dd3baf12)
- 5. Review workflow run logs from March 3-10, 2026 for signs of compromise and potential data exfiltration
- 6. Rotate any credentials that may have been compromised during the attack window
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,608.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-31976 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-31976 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data