CVE-2026-31976 Vulnerability Analysis & Exploit Details

CVE-2026-31976
Vulnerability Scoring

9.8
/10
Critical Risk

As a catastrophic security flaw, CVE-2026-31976 has severe implications, demanding immediate intervention.

Attack Complexity Details

  • Attack Complexity: Low
    Exploits can be performed without significant complexity or special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • Privileges Required: None
    No privileges are required for exploitation.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2026-31976 Details

Status: Analyzed

Last updated: 🕖 16 Mar 2026, 19:02 UTC
Originally published on: 🕗 11 Mar 2026, 20:16 UTC

Time between publication and last update: 4 days

CVSS Release: version 3

CVSS3 Source

nvd@nist.gov

CVSS3 Type

Primary

CVSS3 Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVE-2026-31976 Vulnerability Summary

CVE-2026-31976: 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.

Assessing the Risk of CVE-2026-31976

Access Complexity Graph

The exploitability of CVE-2026-31976 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2026-31976

With low attack complexity and no required privileges, CVE-2026-31976 is an easy target for cybercriminals. Organizations should prioritize immediate mitigation measures to prevent unauthorized access and data breaches.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2026-31976, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2026-31976, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: High
    Exploiting CVE-2026-31976 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: High
    CVE-2026-31976 could allow unauthorized modifications to data, potentially affecting system reliability and trust.
  • Availability: High
    CVE-2026-31976 can disrupt system operations, potentially causing complete denial of service (DoS).

CVE-2026-31976 References

External References

CWE Common Weakness Enumeration

CWE-506

CAPEC Common Attack Pattern Enumeration and Classification

  • Infected Software CAPEC-442 An adversary adds malicious logic, often in the form of a computer virus, to otherwise benign software. This logic is often hidden from the user of the software and works behind the scenes to achieve negative impacts. Many times, the malicious logic is inserted into empty space between legitimate code, and is then called when the software is executed. This pattern of attack focuses on software already fielded and used in operation as opposed to software that is still under development and part of the supply chain.
  • Embed Virus into DLL CAPEC-448 An adversary tampers with a DLL and embeds a computer virus into gaps between legitimate machine instructions. These gaps may be the result of compiler optimizations that pad memory blocks for performance gains. The embedded virus then attempts to infect any machine which interfaces with the product, and possibly steal private data or eavesdrop.
  • Hiding Malicious Data or Code within Files CAPEC-636 Files on various operating systems can have a complex format which allows for the storage of other data, in addition to its contents. Often this is metadata about the file, such as a cached thumbnail for an image file. Unless utilities are invoked in a particular way, this data is not visible during the normal use of the file. It is possible for an attacker to store malicious data or code using these facilities, which would be difficult to discover.

Protect Your Infrastructure against CVE-2026-31976: Combat Critical CVE Threats

Stay updated with real-time CVE vulnerabilities and take action to secure your systems. Enhance your cybersecurity posture with the latest threat intelligence and mitigation techniques. Develop the skills necessary to defend against CVEs and secure critical infrastructures. Join the top cybersecurity professionals safeguarding today's infrastructures.

Other 5 Recently Published CVEs Vulnerabilities

  • CVE-2026-40688 – A out-of-bounds write vulnerability in Fortinet FortiWeb 8.0.0 through 8.0.3, FortiWeb 7.6.0 through 7.6.6, FortiWeb 7.4.0 through 7.4.11 may allow...
  • CVE-2026-39399 – NuGet Gallery is a package repository that powers nuget.org. A security vulnerability exists in the NuGetGallery backend job’s handling of .nuspec ...
  • CVE-2026-39387 – BoidCMS is an open-source, PHP-based flat-file CMS for building simple websites and blogs, using JSON as its database. Versions prior to 2.1.3 are ...
  • CVE-2026-35589 – nanobot is a personal AI assistant. Versions prior to 0.1.5 contain a Cross-Site WebSocket Hijacking (CSWSH) vulnerability exists in the bridge's W...
  • CVE-2026-35034 – Jellyfin is an open source self hosted media server. Versions prior to 10.11.7 contain a denial of service vulnerability in the SyncPlay group crea...