A vulnerability is a weakness or flaw in software, hardware, or a process that an attacker can exploit to gain unauthorized access, disrupt operations, or steal data. Vulnerabilities can exist in application code, system configurations, network architectures, or even organizational procedures, and they range from simple coding errors to complex design flaws.
A vulnerability is any weakness that could be exploited to compromise the security of a system. In software, vulnerabilities are typically bugs or design flaws that allow an attacker to do something the system's creators didn't intend: read data they shouldn't access, execute code they shouldn't run, or bypass controls that should have stopped them.
Vulnerabilities are cataloged using the Common Vulnerabilities and Exposures (CVE) system, which assigns a unique identifier (like CVE-2024-3094) to each publicly disclosed vulnerability. As of 2025, the CVE database contains over 200,000 entries, and new vulnerabilities are published at a rate of roughly 80 to 100 per day.
Not all vulnerabilities are equal. They vary across several dimensions:
According to IBM's 2025 Cost of a Data Breach report, the average cost of a data breach is $4.44 million globally, and most breaches begin with an exploited vulnerability or stolen credential. For startups, a single exploited vulnerability can mean lost customer trust, failed compliance audits, or the kind of security incident that derails a fundraise.
Here's the challenge:
Fencer provides a unified view of vulnerabilities across your code, cloud, and external attack surface. Rather than juggling separate SAST, SCA, CSPM, and EASM tools, Fencer consolidates findings into a single prioritized queue that accounts for CVSS severity, EPSS exploitation probability, KEV status, and the specific context of your environment. The result: your team sees the 10 vulnerabilities that matter this week, not the 500 that technically exist.
A vulnerability is a weakness in a system. An exploit is the technique or code an attacker uses to take advantage of that weakness. Think of a vulnerability as an unlocked window and an exploit as someone climbing through it. A vulnerability can exist without anyone exploiting it, and security teams aim to find and fix vulnerabilities before exploits are developed. Not all vulnerabilities have known exploits, and those without exploits generally pose lower immediate risk (which is why EPSS and KEV are valuable prioritization tools).
Vulnerabilities are found through several channels: automated scanning tools (SAST, DAST, SCA, CSPM) that check code and configurations against known patterns, manual security research and penetration testing by security professionals, bug bounty programs where external researchers report findings for rewards, and vendor security teams who discover issues in their own products. Once discovered, vulnerabilities are typically disclosed through a coordinated process: the finder notifies the vendor, the vendor develops a patch, and the vulnerability is publicly disclosed with a CVE identifier once a fix is available.
Use a risk-based approach combining three signals. CVSS tells you how technically severe the vulnerability is (0-10 scale). EPSS estimates the probability it will be exploited in the next 30 days (0-100%). CISA's KEV catalog confirms whether it's already being actively exploited. Prioritize vulnerabilities that score high across multiple signals, and factor in your own context: a medium-severity vulnerability in your production API handling customer data is more urgent than a critical vulnerability in an isolated test environment. Document your remediation SLAs (such as critical within 24 hours, high within 7 days) for compliance evidence.
