CVE-2026-50812

What it actually does

This vulnerability is a denial-of-service flaw in the SQLite Session Extension. When sqlite3changeset_apply_v3() processes a malformed or corrupt changeset blob, execution can reach sqlite3_value_type() with a NULL sqlite3_value pointer, causing a NULL pointer dereference and process crash. The impact is availability-only: there is no known confidentiality or integrity impact, and exploitation requires the attacker to be able to provide a crafted changeset blob to software that uses the SQLite Session Extension.

Why it matters to the business

Applications or services that accept, synchronize, import, replicate, or otherwise process untrusted SQLite changeset data may be crashed by a malformed input. In operational terms, this can interrupt embedded applications, synchronization workflows, local services, import pipelines, mobile or desktop applications, and any product bundling a vulnerable SQLite build. The CVSS score is moderate and EPSS is very low, with no known KEV listing or ransomware association, so broad exploitation is not currently indicated; however, the issue can still be disruptive where SQLite changeset processing is exposed to untrusted users or automated data feeds.

How an attack unfolds

An attacker first identifies software that uses SQLite 3.53.1 or an affected trunk build with the Session Extension enabled and that accepts changeset blobs from a user-controlled source. The attacker crafts a malformed changeset designed to trigger the vulnerable code path during sqlite3changeset_apply_v3(). When the application applies the changeset, SQLite processes the corrupt structure and eventually calls sqlite3_value_type() with a NULL sqlite3_value pointer. This causes the process to dereference NULL and terminate abnormally. Depending on how the application is deployed, the result may be a one-time application crash, repeated service restarts, failed synchronization jobs, or persistent denial of service if the malformed changeset is retried automatically.

How to fix it

Upgrade SQLite to a build that includes the upstream fix at or after check-in e807d4e3798efd53. If a packaged fixed release is available from the operating system, language runtime, application vendor, or embedded product supplier, apply that update rather than relying only on the system SQLite version, because many products statically bundle SQLite. For applications that directly embed SQLite source, rebuild with the patched SQLite source and redeploy all affected binaries. As a mitigation, restrict the ability to submit changeset blobs to trusted sources only, validate and reject malformed changesets before applying them, disable unused SQLite Session Extension functionality where feasible, quarantine changesets that cause processing failures, and avoid automatic infinite retries of failed changeset application jobs.

How to confirm the fix worked

Confirm the deployed SQLite library or embedded source includes the fix at or after check-in e807d4e3798efd53 and is not SQLite 3.53.1 or an earlier vulnerable trunk build. Inventory both dynamically linked and statically bundled SQLite copies in applications, containers, appliances, mobile apps, and desktop clients. Where safe, run a negative test using malformed changeset inputs in a non-production environment and verify the application rejects the input without crashing. Review build artifacts, software bills of materials, package metadata, and vendor advisories to confirm the patched SQLite code is actually present in the delivered product.

Typical attack path

1. Identify an application or service that uses SQLite with the Session Extension enabled.
2. Determine whether the application accepts SQLite changeset blobs, synchronization payloads, import files, or replication data from a user-controllable source.
3. Craft or obtain a malformed changeset blob that reaches the vulnerable sqlite3changeset_apply_v3() parsing path.
4. Submit the malformed changeset to the target application through the normal import, sync, replication, or processing workflow.
5. Trigger application processing of the changeset.
6. Cause a NULL pointer dereference in sqlite3_value_type(), resulting in a crash of the affected process.
7. Repeat submission or rely on automatic retry behavior to sustain disruption if the application does not quarantine the bad input.

How to detect it

To determine whether exploitation may have occurred, review application logs, crash dumps, service manager logs, endpoint telemetry, and synchronization/import job records for crashes that occur while processing SQLite changesets. Focus on events involving sqlite3changeset_apply_v3(), sqlite3_value_type(), the SQLite Session Extension, malformed changeset errors, segmentation faults, access violations, or repeated failures on the same imported changeset payload. On Linux and Unix-like systems, inspect syslog, journald, core dump metadata, application stderr logs, and crash reporters for SIGSEGV events tied to SQLite call stacks. On Windows, review Windows Error Reporting, Application event logs, crash dumps, and EDR telemetry for application faults involving sqlite3.dll or statically linked SQLite code. Correlate crashes with recent user uploads, sync operations, replication messages, import jobs, or files introduced immediately before the fault. Because the vulnerability produces a crash rather than a distinctive post-exploitation artifact, detection should emphasize timing correlation, repeated crash loops, suspicious changeset sources, and stack traces containing the vulnerable functions.

• sqlite3changeset_apply_v3
• sqlite3_value_type
• SQLite Session Extension
• SIGSEGV
• segmentation fault
• NULL pointer dereference
• access violation
• sqlite3.dll
• libsqlite3.so
• libsqlite3.dylib
• core dumped
• Application Error
• Windows Error Reporting
• Faulting module name: sqlite3.dll
• malformed changeset
• corrupt changeset
• changeset apply failed

What your security team should do

• Prioritize inventory of applications that use SQLite Session Extension features, especially synchronization, replication, import, or changeset-processing functionality exposed to untrusted users or external data feeds.
• Patch or rebuild affected software with SQLite containing check-in e807d4e3798efd53 or a later vendor-provided fixed version.
• Do not assume the operating system SQLite package is the only exposure; search for statically bundled SQLite in application binaries, containers, SDKs, and third-party products.
• Add input controls so changeset blobs are accepted only from authenticated, authorized, and trusted sources.
• Implement error handling that quarantines malformed changesets and prevents repeated crash loops or automatic retry storms.
• Monitor crash telemetry and application logs for segmentation faults, access violations, or stack traces involving sqlite3changeset_apply_v3() and sqlite3_value_type().
• Treat repeated crashes during changeset import or synchronization as potentially malicious even though there is currently no known public exploit maturity or KEV listing.