Summary
Out of bounds access in compact_arena
Affected versions of this crate did not properly implement the generativity, because the invariant lifetimes were not necessarily dropped.
This allows an attacker to mix up two arenas, using indices created from one arena with another one. This might lead to an out-of-bounds read or write access into the memory reserved for the arena.
The flaw was corrected by implementing generativity correctly in version 0.4.0.
Impact
A read operation accesses a memory location beyond the intended buffer boundary. Typical impact: sensitive data disclosure or crash.
CVE-2019-16139 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no 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 (0.4.0); 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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Frequently Asked Questions
- What is CVE-2019-16139? CVE-2019-16139 is a critical-severity out-of-bounds read vulnerability in compact_arena (rust), affecting versions < 0.4.0. It is fixed in 0.4.0. A read operation accesses a memory location beyond the intended buffer boundary.
- How severe is CVE-2019-16139? CVE-2019-16139 has a CVSS score of 9.8 (Critical). 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 compact_arena are affected by CVE-2019-16139? compact_arena (rust) versions < 0.4.0 is affected.
- Is there a fix for CVE-2019-16139? Yes. CVE-2019-16139 is fixed in 0.4.0. Upgrade to this version or later.
- Is CVE-2019-16139 exploitable, and should I be worried? Whether CVE-2019-16139 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-2019-16139 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-2019-16139? Upgrade
compact_arenato 0.4.0 or later.