Summary
sqlite3-ruby: Use-After-Free in SQLite Aggregate Arguments in Heap-Allocated Argument Array
Using Database#create_aggregate, #create_aggregate_handler, or Database#define_aggregator to define an aggregate function that takes two or more arguments, and then evaluating it over TEXT or BLOB column values, can free the Ruby objects holding those arguments while a later argument is still being converted, during ordinary garbage collection. The aggregate's step method then receives an incorrect object, or the process crashes with a segmentation fault.
Mitigation
Upgrade to sqlite3 gem v2.9.6 or later.
There is no reliable workaround. If you cannot upgrade, avoid defining aggregate functions that take two or more arguments. Restricting column value sizes is not a mitigation: smaller values make the defect fire less often but do not prevent it.
Severity
The sqlite3-ruby maintainers assess this as Medium severity (CVSS 4.0 score 6.3). It is reached through ordinary garbage collection without any unusual code structuring: an application is exposed whenever it evaluates a multi-argument aggregate over TEXT or BLOB values whose size an attacker can influence. The demonstrated impact is an incorrect value passed to the aggregate's step method, or a process crash; no controlled memory write or general denial-of-service exploit has been demonstrated.
Credits
Reported by Jeremy Daer (@jeremy).
Impact
Memory is accessed after it has been freed, leading to undefined behavior in native code. Typical impact: memory corruption, crash, or potential code execution.
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 GHSA-MWM8-39RW-8826? GHSA-MWM8-39RW-8826 is a medium-severity use after free vulnerability in sqlite3 (rubygems), affecting versions >= 1.4.0, <= 2.9.5. It is fixed in 2.9.6. Memory is accessed after it has been freed, leading to undefined behavior in native code.
- Which versions of sqlite3 are affected by GHSA-MWM8-39RW-8826? sqlite3 (rubygems) versions >= 1.4.0, <= 2.9.5 is affected.
- Is there a fix for GHSA-MWM8-39RW-8826? Yes. GHSA-MWM8-39RW-8826 is fixed in 2.9.6. Upgrade to this version or later.
- Is GHSA-MWM8-39RW-8826 exploitable, and should I be worried? Whether GHSA-MWM8-39RW-8826 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 GHSA-MWM8-39RW-8826 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 GHSA-MWM8-39RW-8826? Upgrade
sqlite3to 2.9.6 or later.