Summary
Grav CMS, Improper Handling of Highly Compressed Data in Installer::unZip()
Impact
An authenticated administrator (admin.super) can:
- Fill the server disk with highly compressed data (196:1 ratio with simple repeating data, up to 10^11:1 with nested ZIP bombs)
- Exhaust inodes via thousands of small files
- Trigger a PHP stack overflow via deep directory nesting that prevents cleanup, leaving files on disk permanently
- Partially or fully deny service to all users (both authenticated and unauthenticated)
CVE-2026-59193 has a CVSS score of 4.9 (Medium). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.0.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-59193? CVE-2026-59193 is a medium-severity security vulnerability in getgrav/grav (composer), affecting versions >= 1.0.0, < 2.0.0. It is fixed in 2.0.0.
- How severe is CVE-2026-59193? CVE-2026-59193 has a CVSS score of 4.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of getgrav/grav are affected by CVE-2026-59193? getgrav/grav (composer) versions >= 1.0.0, < 2.0.0 is affected.
- Is there a fix for CVE-2026-59193? Yes. CVE-2026-59193 is fixed in 2.0.0. Upgrade to this version or later.
- Is CVE-2026-59193 exploitable, and should I be worried? Whether CVE-2026-59193 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-59193 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-59193? Upgrade
getgrav/gravto 2.0.0 or later.