What Is CVE (Common Vulnerabilities and Exposures)?

Common Vulnerabilities and Exposures (CVE) is a standardized system for identifying and cataloging publicly known cybersecurity vulnerabilities.

What Is the Meaning of CVE?

Common Vulnerabilities and Exposures (CVE) is a public, standardized identification system for cybersecurity vulnerabilities, where each entry assigns a unique ID (the CVE identifier) to a specific, publicly disclosed security issue. A CVE record acts as a consistent reference label that security tools, advisories, patch notes, and incident reports can all point to, so everyone is talking about the same underlying flaw even when vendors or products describe it differently.

Importantly, a CVE entry is not a severity score or a fix by itself. Rather, it’s an index entry that typically includes a short description and references to authoritative sources (such as vendor advisories or technical analyses), enabling organizations to track affected products, map the issue to internal assets, prioritize remediation, and verify whether they are exposed.

How CVE Works?

CVE works by turning a reported vulnerability into a standardized record that the whole security ecosystem can reference, so tools and teams can track the same issue consistently from disclosure through remediation. Here is exactly how it works:

1. A potential vulnerability is found and reported. Researchers, vendors, or users identify a security flaw and share enough details to describe what’s affected and why it matters, which starts the formal tracking process.
2. A CVE Numbering Authority (CNA) reviews the report. The CNA (often the vendor or a coordinating organization) validates that it represents a distinct vulnerability and gathers the minimum required information to identify it clearly.
3. A CVE ID is reserved and assigned. The CNA reserves a unique identifier (for example, CVE-YYYY-NNNNN), which gives everyone a stable handle to reference while analysis and coordination continue.
4. The vulnerability is scoped and documented. Affected products/versions, the nature of the flaw, and reliable references are clarified, which reduces confusion and helps downstream consumers map the issue to real systems.
5. The CVE record is published to the CVE List. The entry becomes publicly visible in the central catalog, making it discoverable to security tools, vulnerability databases, and advisory feeds.
6. Severity and exploitability are assessed elsewhere (often via CVSS). Scoring and richer analysis are typically provided by vendors, NVD, or other sources, which helps organizations prioritize patching even though it’s separate from the CVE ID itself.
7. Organizations use the CVE ID to drive remediation and verification. Teams match CVEs to assets, apply patches or mitigations, and then confirm exposure is resolved, using the CVE as the common reference across scanners, tickets, and reports.

CVE Format

A CVE identifier is written in the form CVE-YYYY-NNNNN (with the last part sometimes longer), where each piece helps make the ID unique and easy to reference. Here is what it includes:

• CVE: the prefix that marks it as a Common Vulnerabilities and Exposures ID.
• YYYY: the year the CVE ID was assigned or reserved (not necessarily the year the bug was discovered or publicly disclosed).
• NNNNN…: a numeric sequence that uniquely identifies the vulnerability within that year. It’s at least four digits and can be more than four (there’s no fixed maximum length today), which allows many IDs to be issued in a single year.

Example: CVE-2024-3094.

What Is an Example of a Common Vulnerability and Exposure?

A well-known example is Log4Shell (CVE-2021-44228), a critical remote code execution vulnerability in the Apache Log4j Java logging library that allowed attackers to trigger the application to load and run attacker-controlled code by sending a specially crafted string that Log4j would resolve (often through logged input).

What Qualifies as a Common Vulnerability and Exposure?

A CVE is assigned when there’s a distinct, security-relevant weakness that can be clearly described and tracked as its own issue, typically a flaw in a specific product/codebase that can be exploited to cause negative impact (for example to confidentiality, integrity, or availability). CNAs are authorized to assign CVE IDs for vulnerabilities within their defined scope and publish them with the first public announcement.

In practice, an issue generally qualifies when it meets all of these conditions:

• It represents one identifiable vulnerability (not a vague class of problems).
• There is enough information to write a meaningful description and point to authoritative references.
• It passes the CNA’s inclusion decision process (otherwise it may be rejected as non-qualifying or improperly reported).

Common Vulnerability Scoring System (CVSS)

The Common Vulnerability Scoring System (CVSS) is an open standard for describing a vulnerability’s technical severity in a consistent way and producing a numeric score from 0.0 to 10.0, often mapped to labels like Low/Medium/High/Critical. It’s meant to help teams compare vulnerabilities using the same yardstick, but it’s not the same thing as risk, because risk depends on your environment, exposure, and business impact.

CVSS works by selecting values for a defined set of metrics and combining them into a score. In CVSS v3.x, metrics are grouped into Base, Temporal, and Environmental. In CVSS v4.0, the groups are Base, Threat, Environmental, and Supplemental, reflecting a clearer separation between “intrinsic severity,” “things that change over time,” and “your local context.”

How Are CVEs Identified?

CVEs are identified through a coordinated process where an actual vulnerability report is reviewed and then given a unique CVE ID by an authorized organization, so everyone can refer to the same issue consistently. Here is how to identify it:

1. A vulnerability is discovered and reported to the affected vendor or to a CVE Numbering Authority (CNA) (an organization authorized to assign CVE IDs).
2. The CNA validates and scopes the issue, confirming it represents a distinct vulnerability and gathering enough detail to describe it and link to reliable references.
3. A CVE ID is reserved/assigned (e.g., CVE-2026-12345), which creates a stable identifier that tools, advisories, and tickets can all use, even while details are still being finalized.
4. The CVE record is published when the CNA populates the record (description + references), moving it from a “RESERVED” state to a public entry in the CVE List.
5. If the issue turns out not to qualify or is otherwise withdrawn, the record can be marked REJECTED rather than published as a valid CVE.

The Benefits and Limitations of CVE

CVE makes it easier to track and communicate vulnerabilities by giving each issue a consistent ID that tools, vendors, and security teams can all reference. At the same time, CVE is only an identification system, so it doesn’t guarantee complete coverage, provide a fix, or reflect the real-world risk of a vulnerability in your specific environment.

Common Vulnerabilities and Exposures Benefits

CVE provides a shared way to reference vulnerabilities, which reduces ambiguity and helps security work move faster across vendors, tools, and teams. The main benefits include:

• Standardized naming across the ecosystem. A single CVE ID prevents confusion caused by different vendor names or multiple write-ups for the same issue, making communication and reporting consistent.
• Easier tracking from discovery to remediation. CVE IDs act as durable identifiers you can use in tickets, patch notes, and audits to follow an issue through investigation, mitigation, and verification.
• Better interoperability between security tools. Scanners, SIEM/SOAR platforms, CMDBs, and vulnerability databases can all key off the same CVE ID, improving correlation and reducing duplicate work.
• Faster vulnerability intelligence and coordination. Public advisories, exploit write-ups, and vendor bulletins can be linked through the CVE record, helping teams gather context quickly without chasing multiple naming schemes.
• Clearer compliance and audit evidence. When policies require tracking known vulnerabilities, CVEs provide an accepted reference that supports consistent reporting and documentation.
• More reliable prioritization inputs when paired with scoring and context. CVE IDs let you join data like CVSS, exploit activity, asset exposure, and business criticality, which makes remediation prioritization more structured.

Common Vulnerabilities and Exposures Limitations

CVE is valuable for identification and coordination, but it has boundaries that matter when you’re prioritizing and managing real-world risk. The common limitations are:

• CVE is an ID system, not a risk rating. A CVE entry doesn’t tell you how urgent it is for your environment; you still need context like exposure, compensating controls, and business impact (often alongside CVSS and threat intel).
• Coverage isn’t guaranteed. Not every security issue receives a CVE, especially product-specific flaws that aren’t publicly disclosed, issues outside CNA scope, or vulnerabilities that don’t meet assignment criteria.
• Record detail can be minimal or uneven. Some CVE descriptions and references are brief, and the depth/quality of information varies by vendor or CNA, which can make impact assessment harder.
• CVE entries don’t include fixes by default. The CVE may link to advisories, but patch availability, mitigation steps, and workarounds come from vendors and other sources, but not from the CVE system itself.
• Timing can lag real-world activity. A vulnerability might be exploited in the wild before a CVE is published, or a CVE may be reserved long before full details are available, creating gaps for defenders.
• CVE granularity doesn’t always match how you patch. A single CVE can affect many versions/products, and some fixes address multiple CVEs at once, so mapping “CVE → patch action” isn’t always one-to-one.

CVE FAQ

Here are the answers to the most commonly asked questions about CVE.

CVE vs. CWE

Who Manages CVEs?

CVEs are managed through the CVE Program, which is overseen by the CVE Board and operated day-to-day by the CVE Secretariat (currently The MITRE Corporation). In practice, most CVE IDs and records are created by a global network of CVE Numbering Authorities (CNAs), typically vendors and security organizations authorized to assign CVE IDs within a defined scope, while the Board provides program governance and the Secretariat supports operations, quality, and coordination.

How Often Are CVEs Updated and Published?

CVEs don’t follow a weekly or monthly release cycle. They’re published continuously as CVE Numbering Authorities (CNAs) finish populating and releasing records to the official CVE List, and individual CVE records can be updated at any time if new details or references become available. Downstream, the U.S. National Vulnerability Database (NVD) checks the CVE List hourly to ingest new publications, rejections, and modifications (but NVD’s added analysis, like scoring and enrichment, may appear later).

Is CVE Data Free?

Yes. CVE data is free and publicly available to anyone. The CVE Program makes the official CVE List available without licensing fees or usage restrictions, so organizations, security vendors, researchers, and individuals can use CVE IDs and records in tools, reports, and services. Some third-party databases may charge for value-added analysis (such as enrichment, prioritization, or dashboards), but the underlying CVE data itself is open.