CVE-2026-51298: SQLite Use After Free Vulnerability

CVE-2026-51298 Overview

CVE-2026-51298 is a use-after-free vulnerability in SQLite version 3.41.0. The flaw exists in the JSON extraction function within src/json.c. After the program releases the JsonParse object via jsonParseFree(), it continues to access internal members of the freed pointer. An attacker with local access can trigger the dangling pointer dereference to crash the SQLite process and cause a denial of service. The vulnerability is tracked under CWE-416: Use After Free.

Critical Impact
Local attackers can crash SQLite by exploiting the freed JsonParse object, producing a denial-of-service condition against any application relying on the JSON extraction function.

Affected Products

SQLite 3.41.0
Applications embedding the affected SQLite library
Services exposing SQLite JSON extraction functions to untrusted input

Discovery Timeline

2026-07-27 - CVE-2026-51298 published to the National Vulnerability Database
2026-07-29 - Last updated in NVD database

Technical Details for CVE-2026-51298

Vulnerability Analysis

The vulnerability resides in the JSON parsing logic of SQLite 3.41.0, implemented in src/json.c. When the JSON extraction function processes input, it constructs a JsonParse object to hold intermediate parser state. The code path releases this object through jsonParseFree(), which returns the underlying memory to the allocator. Execution subsequently reads or writes fields of the freed JsonParse structure through the dangling pointer.

Accessing freed memory produces undefined behavior. In practice, the process crashes or enters an inconsistent state, terminating any database session in progress. Applications that expose JSON functions to attacker-controlled queries inherit the exposure. The attack requires local access and no privileges or user interaction, and it affects availability only.

Root Cause

The root cause is missing lifetime management for the JsonParse object. The function jsonParseFree() deallocates the object, but a subsequent code path in the JSON extraction routine still holds and dereferences the original pointer. The developer did not null the pointer or restructure control flow to prevent post-free access, resulting in a classic CWE-416 condition.

Attack Vector

An attacker must supply crafted input to a SQLite JSON extraction call, such as json_extract(), executed by the vulnerable process. The path is local, so the attacker typically operates as a local user or through an application that forwards untrusted JSON payloads to SQLite. Successful exploitation crashes the SQLite process and denies service to any dependent workload. No memory disclosure or code execution is reported for this flaw.

See the GitHub CVE Advisory and the SQLite json.c source for the affected code location.

Detection Methods for CVE-2026-51298

Indicators of Compromise

Unexpected crashes or segmentation faults in processes linked against libsqlite3 version 3.41.0
Core dumps whose stack traces include jsonParseFree and JSON extraction functions in src/json.c
Repeated abnormal terminations of database-backed services following JSON query workloads

Detection Strategies

Inventory installed SQLite versions across endpoints and servers, flagging any instance at 3.41.0
Instrument test builds with AddressSanitizer to surface use-after-free access on the JsonParse object during fuzzing of json_extract() inputs
Correlate application error logs with operating-system crash telemetry to identify JSON-related SQLite failures

Monitoring Recommendations

Alert on repeated process crashes for applications that embed SQLite and expose JSON functions
Monitor query logs for unusual or malformed JSON payloads submitted to json_extract() and related functions
Track file integrity of libsqlite3 binaries to confirm patched versions remain in place after deployment

How to Mitigate CVE-2026-51298

Immediate Actions Required

Upgrade SQLite to a version later than 3.41.0 that addresses the JSON extraction use-after-free
Audit applications that pass untrusted input to SQLite JSON functions and restrict exposure until patched
Rebuild and redeploy statically linked binaries after updating the SQLite dependency

Patch Information

No vendor advisory URL is listed in the enriched data. Consult upstream commits in the SQLite source repository and the GitHub CVE Advisory for fix references. Update to the latest stable SQLite release provided by your operating system vendor or the upstream project.

Workarounds

Disable or block application code paths that invoke json_extract() and related JSON functions on attacker-controlled input
Enforce strict input validation on JSON strings before passing them to SQLite queries
Run SQLite-backed services under process supervisors that isolate crashes and restart cleanly to limit denial-of-service impact

bash

# Verify installed SQLite version and upgrade if 3.41.0 is present
sqlite3 --version
# If output begins with 3.41.0, upgrade via the platform package manager, e.g.:
#   apt-get update && apt-get install --only-upgrade sqlite3 libsqlite3-0
#   dnf upgrade sqlite sqlite-libs