sqlite3-ruby EUVD-2026-49899

Requires all of the following in the host Ruby application itself: an aggregate function defined via Database#create_aggregate, #create_aggregate_handler, or #define_aggregator; a prepared statement that calls that aggregate left open; an explicit Database#close (or #discard); a garbage-collection cycle that frees the aggregator; and then a subsequent step call on the now-stale statement. There is no remote or network vector and no external attacker-supplied input - the trigger is an in-process API misuse pattern (AV:L). Exploitation is limited to sqlite3/sqlite3-ruby gem versions >= 2.1.0 and <= 2.9.4; upgrading to 2.9.5 or avoiding aggregate calls after closing the database eliminates it. Practical impact is a process segfault/crash, not a proven denial-of-service or code-execution primitive.

All available signals converge on low real-world risk. The vendor-supplied CVSS 4.0 vector (AV:L/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L, base score 2.0) describes a local, high-complexity, low-privilege-requiring flaw with only partial impact to each of confidentiality, integrity and availability - consistent with the sqlite3-ruby maintainers' own self-assessment of Low severity. EPSS is 0.11% (1st percentile), SSVC returns Exploitation: none / Automatable: no / Technical Impact: partial, there is no CISA KEV listing, and no public exploit code was identified - no public exploit identified at time of analysis. Critically, the flaw is not remotely triggerable: it requires the affected Ruby application's own code to (1) define an aggregate function, (2) keep an open prepared statement, (3) explicitly close the database, and then (4) step that statement after GC - i.e., the 'attacker' is essentially the application's own buggy call sequence, not an external actor. The vendor explicitly states there is no known general exploit usable as a denial-of-service attack. The 'Memory Corruption' / 'Use After Free' framing is technically accurate (CWE-416) but the practical outcome is an invalid read and segfault (process crash), not a demonstrated code-execution primitive. This is a genuine low-priority bug: fix during normal dependency maintenance, not an emergency.

A Ruby application defines a SQLite aggregate function via Database#create_aggregate/#create_aggregate_handler/#define_aggregator, prepares a statement that calls it, then explicitly closes the database while the prepared statement remains open. After garbage collection frees the aggregator, calling step on that stale statement dereferences freed memory, causing an invalid read and a segmentation fault that crashes the process. No public exploit exists; triggering requires this specific in-process coding pattern rather than any remote or attacker-supplied input.